diff --git a/js/bullet.js b/js/bullet.js
index a726528..f9a0c93 100644
--- a/js/bullet.js
+++ b/js/bullet.js
@@ -108,7 +108,7 @@ const b = {
           mask: cat.map | cat.body | cat.mob | cat.mobBullet | cat.mobShield
         },
         minDmgSpeed: 10,
-        onDmg() {}, //this.endCycle = 0  //triggers despawn
+        beforeDmg() {}, //this.endCycle = 0  //triggers despawn
         onEnd() {}
       };
     } else {
@@ -125,7 +125,7 @@ const b = {
           mask: cat.map | cat.body | cat.mob | cat.mobBullet | cat.mobShield
         },
         minDmgSpeed: 10,
-        onDmg() {}, //this.endCycle = 0  //triggers despawn
+        beforeDmg() {}, //this.endCycle = 0  //triggers despawn
         onEnd() {}
       };
     }
@@ -276,13 +276,13 @@ const b = {
       }
     }
   },
-  missile(where, dir, speed, size = 1, spawn = 0) {
+  missile(where, angle, speed, size = 1, spawn = 0) {
     const me = bullet.length;
-    bullet[me] = Bodies.rectangle(where.x, where.y, 30 * size, 4 * size, b.fireAttributes(dir));
+    bullet[me] = Bodies.rectangle(where.x, where.y, 30 * size, 4 * size, b.fireAttributes(angle));
     const thrust = 0.00417 * bullet[me].mass;
     Matter.Body.setVelocity(bullet[me], {
-      x: mech.Vx / 2 + speed * Math.cos(dir),
-      y: mech.Vy / 2 + speed * Math.sin(dir)
+      x: mech.Vx / 2 + speed * Math.cos(angle),
+      y: mech.Vy / 2 + speed * Math.sin(angle)
     });
     World.add(engine.world, bullet[me]); //add bullet to world
     bullet[me].frictionAir = 0.023
@@ -300,7 +300,7 @@ const b = {
         }
       }
     }
-    bullet[me].onDmg = function () {
+    bullet[me].beforeDmg = function () {
       this.tryToLockOn();
       this.endCycle = 0; //bullet ends cycle after doing damage  // also triggers explosion
     };
@@ -557,7 +557,7 @@ const b = {
       endCycle: Infinity,
       lookFrequency: 0,
       range: 700,
-      onDmg() {},
+      beforeDmg() {},
       do() {
         this.force.y += this.mass * 0.002; //extra gravity
         let collide = Matter.Query.collides(this, map) //check if collides with map
@@ -686,7 +686,7 @@ const b = {
         x: 100 * (Math.random() - 0.5),
         y: 100 * (Math.random() - 0.5)
       },
-      onDmg(who) {
+      beforeDmg(who) {
         this.endCycle = 0; //bullet ends cycle after doing damage 
         if (this.isFreeze) mobs.statusSlow(who, 60)
       },
@@ -800,7 +800,7 @@ const b = {
       minDmgSpeed: 0,
       lockedOn: null,
       isFollowMouse: true,
-      onDmg(who) {
+      beforeDmg(who) {
         mobs.statusSlow(who, 60)
         this.endCycle = game.cycle
         if (mod.isHeavyWater) mobs.statusDoT(who, 0.15, 300)
@@ -877,7 +877,7 @@ const b = {
       isFollowMouse: true,
       deathCycles: 110 + RADIUS * 5,
       isImproved: false,
-      onDmg(who) {
+      beforeDmg(who) {
         //move away from target after hitting
         const unit = Vector.mult(Vector.normalise(Vector.sub(this.position, who.position)), -20)
         Matter.Body.setVelocity(this, {
@@ -1002,7 +1002,7 @@ const b = {
       target: null,
       targetVertex: null,
       targetRelativePosition: null,
-      onDmg(who) {
+      beforeDmg(who) {
         if (!this.target && who.alive) {
           this.target = who;
           if (who.radius < 20) {
@@ -1154,15 +1154,14 @@ const b = {
   },
   nail(pos, velocity, dmg = 0) {
     const me = bullet.length;
-    // bullet[me] = Bodies.rectangle(pos.x, pos.y, 25, 2, b.fireAttributes(Math.atan2(velocity.y, velocity.x)));
     bullet[me] = Bodies.rectangle(pos.x, pos.y, 25 * mod.biggerNails, 2 * mod.biggerNails, b.fireAttributes(Math.atan2(velocity.y, velocity.x)));
-
     Matter.Body.setVelocity(bullet[me], velocity);
     World.add(engine.world, bullet[me]); //add bullet to world
     bullet[me].endCycle = game.cycle + 60 + 18 * Math.random();
     bullet[me].dmg = dmg
-    bullet[me].onDmg = function (who) {
+    bullet[me].beforeDmg = function (who) {
       if (mod.isNailPoison) mobs.statusDoT(who, dmg * 0.22, 120) // one tick every 30 cycles
+      if (mod.isNailCrit && !who.shield && Vector.dot(Vector.normalise(Vector.sub(who.position, this.position)), Vector.normalise(this.velocity)) > 0.99) this.dmg *= 5 //crit if hit near center
     };
     bullet[me].do = function () {};
   },
@@ -1227,7 +1226,7 @@ const b = {
         mask: cat.map | cat.body | cat.bullet | cat.mob | cat.mobBullet | cat.mobShield
       },
       lockedOn: null,
-      onDmg() {
+      beforeDmg() {
         this.lockedOn = null
       },
       onEnd() {},
@@ -1283,7 +1282,7 @@ const b = {
         mask: cat.map | cat.body | cat.bullet | cat.mob | cat.mobBullet | cat.mobShield
       },
       lockedOn: null,
-      onDmg() {
+      beforeDmg() {
         this.lockedOn = null
       },
       onEnd() {},
@@ -1342,7 +1341,7 @@ const b = {
         mask: cat.map | cat.body | cat.bullet | cat.mob | cat.mobBullet | cat.mobShield
       },
       lockedOn: null,
-      onDmg() {
+      beforeDmg() {
         this.lockedOn = null
       },
       onEnd() {},
@@ -1452,7 +1451,7 @@ const b = {
       },
       lockedOn: null,
       explode: 0,
-      onDmg() {
+      beforeDmg() {
         if (this.lockedOn) {
           const explosionRadius = Math.min(170 + 140 * this.isUpgraded, Vector.magnitude(Vector.sub(this.position, mech.pos)) - 30)
           if (explosionRadius > 60) {
@@ -1528,7 +1527,7 @@ const b = {
         mask: cat.map | cat.body | cat.bullet | cat.mob | cat.mobBullet | cat.mobShield
       },
       lockedOn: null,
-      onDmg() {
+      beforeDmg() {
         this.lockedOn = null
       },
       onEnd() {},
@@ -1706,7 +1705,7 @@ const b = {
         category: cat.bullet,
         mask: 0 //cat.map | cat.body | cat.bullet | cat.mob | cat.mobBullet | cat.mobShield
       },
-      onDmg() {},
+      beforeDmg() {},
       onEnd() {},
       range: 190 + 50 * mod.isOrbitBotUpgrade, //range is set in bot upgrade too! //150 + (80 + 100 * mod.isOrbitBotUpgrade) * Math.random(), // + 5 * mod.orbitBotCount,
       orbitalSpeed: 0,
@@ -1850,7 +1849,7 @@ const b = {
           y: mech.Vy / 2 + speed * Math.sin(angle)
         }, dmg) //position, velocity, damage
         if (mod.isIceCrystals) {
-          bullet[bullet.length - 1].onDmg = function (who) {
+          bullet[bullet.length - 1].beforeDmg = function (who) {
             mobs.statusSlow(who, 30)
             if (mod.isNailPoison) mobs.statusDoT(who, dmg * 0.22, 120) // one tick every 30 cycles
           };
@@ -1957,7 +1956,7 @@ const b = {
           bullet[me].do = function () {
             this.force.y += this.mass * 0.001;
           };
-          bullet[me].onDmg = function (who) {
+          bullet[me].beforeDmg = function (who) {
             mobs.statusStun(who, 180) // (2.3) * 2 / 14 ticks (2x damage over 7 seconds)
           };
         } else {
@@ -2031,6 +2030,11 @@ const b = {
                   }
                 } else {
                   this.endCycle = 0;
+                  if (mod.isFlechetteExplode && !who.shield && Vector.dot(Vector.normalise(Vector.sub(who.position, this.position)), Vector.normalise(this.velocity)) > 0.98) {
+                    // mobs.statusStun(who, 120)
+                    this.explodeRad = 250 + 30 * Math.random();
+                    b.explosion(this.position, this.explodeRad); //makes bullet do explosive damage at end
+                  }
                   who.foundPlayer();
                   if (mod.isFastDot) {
                     mobs.statusDoT(who, 3.78, 30)
@@ -2120,7 +2124,7 @@ const b = {
               category: 0,
               mask: 0, //cat.mob | cat.mobBullet | cat.mobShield
             },
-            onDmg() {},
+            beforeDmg() {},
             onEnd() {},
             do() {
               if (!mech.isBodiesAsleep) {
@@ -2309,7 +2313,7 @@ const b = {
           bullet[me].onEnd = function () {
             b.explosion(this.position, this.explodeRad); //makes bullet do explosive damage at end
           }
-          bullet[me].onDmg = function () {
+          bullet[me].beforeDmg = function () {
             this.endCycle = 0; //bullet ends cycle after hitting a mob and triggers explosion
           };
           bullet[me].do = function () {
@@ -2335,7 +2339,7 @@ const b = {
           if (mod.grenadeFragments) b.targetedNail(this.position, mod.grenadeFragments)
         }
         bullet[me].minDmgSpeed = 1;
-        bullet[me].onDmg = function () {
+        bullet[me].beforeDmg = function () {
           this.endCycle = 0; //bullet ends cycle after doing damage  //this also triggers explosion
         };
 
@@ -2401,7 +2405,7 @@ const b = {
             if (dist < this.explodeRad) mech.energy = 0 //remove player energy
           }
         }
-        bullet[me].onDmg = function () {
+        bullet[me].beforeDmg = function () {
           // this.endCycle = 0; //bullet ends cycle after doing damage  //this triggers explosion
         };
         bullet[me].radius = 22; //used from drawing timer
@@ -2510,7 +2514,7 @@ const b = {
         bullet[me].maxDamageRadius = (435 + 150 * Math.random()) * (mod.isNeutronImmune ? 1.2 : 1)
         bullet[me].stuckTo = null;
         bullet[me].stuckToRelativePosition = null;
-        bullet[me].onDmg = function () {};
+        bullet[me].beforeDmg = function () {};
         bullet[me].stuck = function () {};
         bullet[me].do = function () {
           function onCollide(that) {
@@ -2682,7 +2686,7 @@ const b = {
         bullet[me].minDmgSpeed = 0;
         bullet[me].totalSpores = 8 + 2 * mod.isFastSpores + 2 * mod.isSporeFreeze
         bullet[me].stuck = function () {};
-        bullet[me].onDmg = function () {};
+        bullet[me].beforeDmg = function () {};
         bullet[me].do = function () {
           function onCollide(that) {
             that.collisionFilter.mask = 0; //non collide with everything
@@ -2850,7 +2854,7 @@ const b = {
       name: "rail gun",
       description: "use <strong class='color-f'>energy</strong> to launch a high-speed <strong>dense</strong> rod<br><strong>hold</strong> left mouse to charge, <strong>release</strong> to fire",
       ammo: 0,
-      ammoPack: 3,
+      ammoPack: 3.5,
       have: false,
       fire() {
         if (mod.isCapacitor) {
@@ -2871,7 +2875,7 @@ const b = {
               },
               minDmgSpeed: 5,
               endCycle: game.cycle + 140,
-              onDmg(who) {
+              beforeDmg(who) {
                 if (who.shield) {
                   for (let i = 0, len = mob.length; i < len; i++) {
                     if (mob[i].id === who.shieldTargetID) { //apply some knock back to shield mob before shield breaks
@@ -2880,10 +2884,10 @@ const b = {
                     }
                   }
                   Matter.Body.setVelocity(this, {
-                    x: -0.1 * this.velocity.x,
-                    y: -0.1 * this.velocity.y
+                    x: -0.5 * this.velocity.x,
+                    y: -0.5 * this.velocity.y
                   });
-                  Matter.Body.setDensity(this, 0.001);
+                  // Matter.Body.setDensity(this, 0.001);
                 }
                 if (mod.isRailNails && this.speed > 10) {
                   b.targetedNail(this.position, (Math.min(40, this.speed) - 10) * 0.6) // 0.6 as many nails as the normal rail gun
@@ -2980,7 +2984,7 @@ const b = {
               mask: cat.map | cat.body | cat.mob | cat.mobBullet | cat.mobShield
             },
             minDmgSpeed: 5,
-            onDmg(who) {
+            beforeDmg(who) {
               if (who.shield) {
                 for (let i = 0, len = mob.length; i < len; i++) {
                   if (mob[i].id === who.shieldTargetID) { //apply some knock back to shield mob before shield breaks
@@ -3472,7 +3476,7 @@ const b = {
     //       },
     //       minDmgSpeed: 5,
     //       range: 0,
-    //       onDmg() {
+    //       beforeDmg() {
     //         this.endCycle = 0;
     //       }, //this.endCycle = 0  //triggers despawn
     //       onEnd() {},
diff --git a/js/engine.js b/js/engine.js
index ab467b4..5092847 100644
--- a/js/engine.js
+++ b/js/engine.js
@@ -173,11 +173,11 @@ function collisionChecks(event) {
           }
           //mob + bullet collisions
           if (obj.classType === "bullet" && obj.speed > obj.minDmgSpeed) {
+            obj.beforeDmg(mob[k]); //some bullets do actions when they hits things, like despawn //forces don't seem to work here
             let dmg = b.dmgScale * (obj.dmg + 0.15 * obj.mass * Vector.magnitude(Vector.sub(mob[k].velocity, obj.velocity)))
             if (mod.isCrit && mob[k].isStunned) dmg *= 4
             mob[k].foundPlayer();
             mob[k].damage(dmg);
-            obj.onDmg(mob[k]); //some bullets do actions when they hits things, like despawn //forces don't seem to work here
             game.drawList.push({ //add dmg to draw queue
               x: pairs[i].activeContacts[0].vertex.x,
               y: pairs[i].activeContacts[0].vertex.y,
diff --git a/js/level.js b/js/level.js
index 3a2f756..217884b 100644
--- a/js/level.js
+++ b/js/level.js
@@ -15,12 +15,12 @@ const level = {
       // game.zoomScale = 1000;
       // game.setZoom();
       // mech.isCloak = true;
-      mech.setField("wormhole")
-      // b.giveGuns("nail gun")
+      // mech.setField("wormhole")
+      // b.giveGuns("flechettes")
       // for (let i = 0; i < 10; i++) {
       // mod.giveMod("laser-bot");
       // }
-      mod.giveMod("cosmic string")
+      // mod.giveMod("supercritical fission")
 
 
       level.intro(); //starting level
@@ -149,10 +149,10 @@ const level = {
     // spawn.sniper(1700, -120, 50)
     // spawn.bomberBoss(1400, -500)
     // spawn.sniper(1800, -120)
-    // spawn.sniper(2200, -120)
     // spawn.cellBossCulture(1600, -500)
-    spawn.powerUpBoss(1600, -500)
-    // spawn.shield(mob[mob.length - 1], 1200, -500, 1);
+    // spawn.powerUpBoss(1600, -500)
+    spawn.sniper(1200, -500)
+    spawn.shield(mob[mob.length - 1], 1200, -500, 1);
 
     // spawn.nodeBoss(1200, -500, "launcher")
     // spawn.snakeBoss(1200, -500)
@@ -3841,7 +3841,7 @@ const level = {
   difficultyIncrease(num = 1) {
     for (let i = 0; i < num; i++) {
       game.difficulty++
-      game.dmgScale += 0.37; //damage done by mobs increases each level
+      game.dmgScale += 0.38; //damage done by mobs increases each level
       b.dmgScale *= 0.93; //damage done by player decreases each level
       if (game.accelScale < 5) game.accelScale *= 1.02 //mob acceleration increases each level
       if (game.lookFreqScale > 0.2) game.lookFreqScale *= 0.98 //mob cycles between looks decreases each level
@@ -3852,7 +3852,7 @@ const level = {
   difficultyDecrease(num = 1) { //used in easy mode for game.reset()
     for (let i = 0; i < num; i++) {
       game.difficulty--
-      game.dmgScale -= 0.37; //damage done by mobs increases each level
+      game.dmgScale -= 0.38; //damage done by mobs increases each level
       if (game.dmgScale < 0.1) game.dmgScale = 0.1;
       b.dmgScale /= 0.93; //damage done by player decreases each level
       if (game.accelScale > 0.2) game.accelScale /= 1.02 //mob acceleration increases each level
@@ -3887,6 +3887,7 @@ const level = {
     if (level.onLevel > level.levels.length - 1) level.onLevel = 0;
     level.difficultyIncrease(game.difficultyMode) //increase difficulty based on modes
     if (level.levelsCleared > level.levels.length) level.difficultyIncrease(game.difficultyMode)
+    if (level.levelsCleared > level.levels.length * 1.25) level.difficultyIncrease(game.difficultyMode)
     if (level.levelsCleared > level.levels.length * 1.5) level.difficultyIncrease(game.difficultyMode)
     if (level.levelsCleared > level.levels.length * 2) level.difficultyIncrease(game.difficultyMode)
     if (game.isEasyMode && level.levelsCleared % 2) level.difficultyDecrease(1);
diff --git a/js/mob.js b/js/mob.js
index 993a959..7069aad 100644
--- a/js/mob.js
+++ b/js/mob.js
@@ -1043,7 +1043,10 @@ const mobs = {
               b.spore(this.position)
             }
           }
-          if (Math.random() < mod.isBotSpawner) b.randomBot(this.position, false)
+          if (Math.random() < mod.isBotSpawner) {
+            b.randomBot(this.position, false)
+            bullet[bullet.length - 1].endCycle = game.cycle + 1500 + Math.floor(600 * Math.random())
+          }
           if (mod.isExplodeMob) b.explosion(this.position, Math.min(550, Math.sqrt(this.mass + 2.5) * 50))
           if (mod.nailsDeathMob) b.targetedNail(this.position, mod.nailsDeathMob, 40 + 7 * Math.random())
         } else if (mod.isShieldAmmo && this.shield) {
diff --git a/js/mods.js b/js/mods.js
index 16c3875..623ce66 100644
--- a/js/mods.js
+++ b/js/mods.js
@@ -408,7 +408,7 @@ const mod = {
             maxCount: 9,
             count: 0,
             allowed() {
-                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField || mod.boomBotCount > 1;
+                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField || mod.boomBotCount > 1 || mod.isFlechetteExplode
             },
             requires: "an explosive damage source",
             effect: () => {
@@ -424,7 +424,7 @@ const mod = {
             maxCount: 1,
             count: 0,
             allowed() {
-                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField || mod.boomBotCount > 1;
+                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField || mod.boomBotCount > 1 || mod.isFlechetteExplode
             },
             requires: "an explosive damage source",
             effect: () => {
@@ -440,7 +440,7 @@ const mod = {
             maxCount: 1,
             count: 0,
             allowed() {
-                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField
+                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.haveGunCheck("pulse") || mod.isMissileField || mod.isFlechetteExplode
             },
             requires: "an explosive damage source",
             effect: () => {
@@ -457,7 +457,7 @@ const mod = {
             maxCount: 1,
             count: 0,
             allowed() {
-                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.isMissileField || mod.isExplodeMob
+                return mod.haveGunCheck("missiles") || mod.haveGunCheck("flak") || mod.haveGunCheck("grenades") || mod.haveGunCheck("vacuum bomb") || mod.isMissileField || mod.isExplodeMob || mod.isFlechetteExplode
             },
             requires: "an explosive damage source",
             effect: () => {
@@ -469,15 +469,15 @@ const mod = {
         },
         {
             name: "scrap bots",
-            description: "<strong>11%</strong> chance to build a <strong>bot</strong> after killing a mob<br>the bot only functions until the end of the level",
-            maxCount: 6,
+            description: "<strong>19%</strong> chance to build a <strong>bot</strong> after killing a mob<br>the bot last for about <strong>30</strong> seconds",
+            maxCount: 3,
             count: 0,
             allowed() {
                 return mod.totalBots() > 0
             },
             requires: "a bot",
             effect() {
-                mod.isBotSpawner += 0.11;
+                mod.isBotSpawner += 0.19;
             },
             remove() {
                 mod.isBotSpawner = 0;
@@ -1596,6 +1596,22 @@ const mod = {
                 mod.isDamageFromBulletCount = false
             }
         },
+        {
+            name: "critical bifurcation",
+            description: "<strong>nails</strong> do <strong>400%</strong> more <strong class='color-d'>damage</strong><br>when they strike near the <strong>center</strong> of a mob",
+            maxCount: 1,
+            count: 0,
+            allowed() {
+                return mod.haveGunCheck("nail gun")
+            },
+            requires: "nail gun",
+            effect() {
+                mod.isNailCrit = true
+            },
+            remove() {
+                mod.isNailCrit = false
+            }
+        },
         {
             name: "pneumatic actuator",
             description: "<strong>nail gun</strong> takes <strong>45%</strong> less time to ramp up<br>to it's shortest <strong>delay</strong> after firing",
@@ -1843,15 +1859,31 @@ const mod = {
                 mod.isFastDot = false;
             }
         },
+        {
+            name: "supercritical fission",
+            description: "<strong>flechettes</strong> can <strong class='color-e'>explode</strong><br>if they strike mobs near their <strong>center</strong>",
+            maxCount: 1,
+            count: 0,
+            allowed() {
+                return mod.haveGunCheck("flechettes") && !mod.pierce
+            },
+            requires: "flechettes and not piercing needles",
+            effect() {
+                mod.isFlechetteExplode = true
+            },
+            remove() {
+                mod.isFlechetteExplode = false
+            }
+        },
         {
             name: "piercing needles",
             description: "<strong>needles</strong> penetrate <strong>mobs</strong> and <strong>blocks</strong><br>potentially hitting <strong>multiple</strong> targets",
             maxCount: 1,
             count: 0,
             allowed() {
-                return mod.haveGunCheck("flechettes")
+                return mod.haveGunCheck("flechettes") && !mod.isFlechetteExplode
             },
-            requires: "flechettes",
+            requires: "flechettes and not supercritical fission",
             effect() {
                 mod.pierce = true;
             },
@@ -2807,7 +2839,7 @@ const mod = {
         },
         {
             name: "cosmic string",
-            description: "when you <strong> tunnel</strong>  through a <strong class='color-worm'>wormhole</strong><br><strong class='color-d'>damage</strong> mobs between the <strong>endpoints</strong>",
+            description: "when you <strong> tunnel</strong> through a <strong class='color-worm'>wormhole</strong><br>mobs between the <strong>endpoints</strong> take <strong class='color-d'>damage</strong>",
             maxCount: 1,
             count: 0,
             allowed() {
@@ -2823,7 +2855,7 @@ const mod = {
         },
         {
             name: "Penrose process",
-            description: "after a <strong>block</strong> falls into a <strong class='color-worm'>wormhole</strong><br>overfill your <strong class='color-f'>energy</strong> to <strong>300%</strong> of your maximum<br> ",
+            description: "after a <strong>block</strong> falls into a <strong class='color-worm'>wormhole</strong><br>your <strong class='color-f'>energy</strong> overfills to <strong>300%</strong> of the maximum",
             maxCount: 1,
             count: 0,
             allowed() {
@@ -2837,6 +2869,39 @@ const mod = {
                 mod.isWormholeEnergy = false
             }
         },
+        {
+            name: "transdimensional spores",
+            description: "when <strong>blocks</strong> fall into a <strong class='color-worm'>wormhole</strong><br>higher dimension <strong class='color-p' style='letter-spacing: 2px;'>spores</strong> are summoned",
+            maxCount: 1,
+            count: 0,
+            allowed() {
+                return mech.fieldUpgrades[mech.fieldMode].name === "wormhole"
+            },
+            requires: "wormhole",
+            effect() {
+                mod.isWormSpores = true
+            },
+            remove() {
+                mod.isWormSpores = false
+            }
+        },
+        {
+            name: "traversable geodesics",
+            description: "your <strong>bullets</strong> can traverse <strong class='color-worm'>wormholes</strong><br>spawn a <strong class='color-g'>gun</strong> power up",
+            maxCount: 1,
+            count: 0,
+            allowed() {
+                return mech.fieldUpgrades[mech.fieldMode].name === "wormhole"
+            },
+            requires: "wormhole",
+            effect() {
+                mod.isWormBullets = true
+                powerUps.spawn(mech.pos.x, mech.pos.y, "gun");
+            },
+            remove() {
+                mod.isWormBullets = false
+            }
+        },
         {
             name: "heals",
             description: "spawn <strong>6</strong> <strong class='color-h'>heal</strong> power ups",
@@ -3074,5 +3139,9 @@ const mod = {
     isPerfectBrake: null,
     explosiveRadius: null,
     isWormholeEnergy: null,
-    isWormholeDamage: null
+    isWormholeDamage: null,
+    isNailCrit: null,
+    isFlechetteExplode: null,
+    isWormSpores: null,
+    isWormBullets: null
 }
\ No newline at end of file
diff --git a/js/player.js b/js/player.js
index 488f210..b7a4cf4 100644
--- a/js/player.js
+++ b/js/player.js
@@ -2240,37 +2240,27 @@ const mech = {
     },
     {
       name: "wormhole",
-      description: "use <strong class='color-f'>energy</strong> to <strong>tunnel</strong> through a <strong class='color-worm'>wormhole</strong><br>bullets may also traverse <strong class='color-worm'>wormholes</strong><br>blocks and power ups can't <strong>exit</strong>",
+      description: "use <strong class='color-f'>energy</strong> to <strong>tunnel</strong> through a <strong class='color-worm'>wormhole</strong><br><strong class='color-worm'>wormholes</strong> attract blocks and power ups", //<br>bullets may also traverse <strong class='color-worm'>wormholes</strong>
       effect: () => {
         game.replaceTextLog = true; //allow text over write
         mech.drop();
         // mech.hole = {  //this is reset with each new field, but I'm leaving it here for reference
         //   isOn: false,
         //   isReady: true,
-        //   pos1: {
-        //     x: 0,
-        //     y: 0
-        //   },
-        //   pos2: {
-        //     x: 0,
-        //     y: 0
-        //   },
+        //   pos1: {x: 0,y: 0},
+        //   pos2: {x: 0,y: 0},
+        //   angle: 0,
+        //   unit:{x:0,y:0},
         // }
         mech.hold = function () {
-
           if (mech.hole.isOn) {
             // draw holes
             mech.fieldRange = 0.97 * mech.fieldRange + 0.03 * (50 + 10 * Math.sin(game.cycle * 0.025))
-
-            //draw bezier curves between the portals
             const semiMajorAxis = mech.fieldRange + 30
-            const sub = Vector.sub(mech.hole.pos1, mech.hole.pos2)
-            const unit = Vector.perp(Vector.normalise(sub))
-            const edge1a = Vector.add(Vector.mult(unit, semiMajorAxis), mech.hole.pos1)
-            const edge1b = Vector.add(Vector.mult(unit, -semiMajorAxis), mech.hole.pos1)
-            const edge2a = Vector.add(Vector.mult(unit, semiMajorAxis), mech.hole.pos2)
-            const edge2b = Vector.add(Vector.mult(unit, -semiMajorAxis), mech.hole.pos2)
-            // const opacity = 200 / mech.fieldRange / mech.fieldRange
+            const edge1a = Vector.add(Vector.mult(mech.hole.unit, semiMajorAxis), mech.hole.pos1)
+            const edge1b = Vector.add(Vector.mult(mech.hole.unit, -semiMajorAxis), mech.hole.pos1)
+            const edge2a = Vector.add(Vector.mult(mech.hole.unit, semiMajorAxis), mech.hole.pos2)
+            const edge2b = Vector.add(Vector.mult(mech.hole.unit, -semiMajorAxis), mech.hole.pos2)
             ctx.beginPath();
             ctx.moveTo(edge1a.x, edge1a.y)
             ctx.bezierCurveTo(mech.hole.pos1.x, mech.hole.pos1.y, mech.hole.pos2.x, mech.hole.pos2.y, edge2a.x, edge2a.y);
@@ -2278,10 +2268,9 @@ const mech = {
             ctx.bezierCurveTo(mech.hole.pos2.x, mech.hole.pos2.y, mech.hole.pos1.x, mech.hole.pos1.y, edge1b.x, edge1b.y);
             ctx.fillStyle = `rgba(255,255,255,${200 / mech.fieldRange / mech.fieldRange})` //"rgba(0,0,0,0.1)"
             ctx.fill();
-            const angle = Math.atan2(sub.y, sub.x)
             ctx.beginPath();
-            ctx.ellipse(mech.hole.pos1.x, mech.hole.pos1.y, mech.fieldRange, semiMajorAxis, angle, 0, 2 * Math.PI)
-            ctx.ellipse(mech.hole.pos2.x, mech.hole.pos2.y, mech.fieldRange, semiMajorAxis, angle, 0, 2 * Math.PI)
+            ctx.ellipse(mech.hole.pos1.x, mech.hole.pos1.y, mech.fieldRange, semiMajorAxis, mech.hole.angle, 0, 2 * Math.PI)
+            ctx.ellipse(mech.hole.pos2.x, mech.hole.pos2.y, mech.fieldRange, semiMajorAxis, mech.hole.angle, 0, 2 * Math.PI)
             ctx.fillStyle = `rgba(255,255,255,${32 / mech.fieldRange})`
             ctx.fill();
 
@@ -2318,20 +2307,6 @@ const mech = {
                 }
               }
             }
-            //teleport bullets
-            for (let i = 0, len = bullet.length; i < len; ++i) { //teleport bullets from hole1 to hole2
-              if (!bullet[i].botType && !bullet[i].isInHole) { //don't teleport bots
-                if (Vector.magnitude(Vector.sub(mech.hole.pos1, bullet[i].position)) < mech.fieldRange) { //find if bullet is touching hole1
-                  Matter.Body.setPosition(bullet[i], Vector.add(mech.hole.pos2, Vector.sub(mech.hole.pos1, bullet[i].position)));
-                  mech.fieldRange += 5
-                  bullet[i].isInHole = true
-                } else if (Vector.magnitude(Vector.sub(mech.hole.pos2, bullet[i].position)) < mech.fieldRange) { //find if bullet is touching hole1
-                  Matter.Body.setPosition(bullet[i], Vector.add(mech.hole.pos1, Vector.sub(mech.hole.pos2, bullet[i].position)));
-                  mech.fieldRange += 5
-                  bullet[i].isInHole = true
-                }
-              }
-            }
             //suck and shrink blocks
             const suckRange = 500
             const shrinkRange = 100
@@ -2354,6 +2329,13 @@ const mech = {
                         body.splice(i, 1);
                         mech.fieldRange *= 0.8
                         if (mod.isWormholeEnergy && mech.energy < mech.maxEnergy * 3) mech.energy = mech.maxEnergy * 3
+                        if (mod.isWormSpores) { //pandimensionalspermia
+                          b.spore(Vector.add(mech.hole.pos2, Vector.rotate({
+                            x: mech.fieldRange,
+                            y: 0
+                          }, 2 * Math.PI * Math.random())))
+                          Matter.Body.setVelocity(bullet[bullet.length - 1], Vector.mult(Vector.rotate(mech.hole.unit, -Math.PI / 2), 15));
+                        }
                         break
                       }
                     }
@@ -2370,45 +2352,58 @@ const mech = {
                       body.splice(i, 1);
                       mech.fieldRange *= 0.8
                       if (mod.isWormholeEnergy && mech.energy < mech.maxEnergy * 3) mech.energy = mech.maxEnergy * 3
+                      if (mod.isWormSpores) { //pandimensionalspermia
+                        b.spore(Vector.add(mech.hole.pos1, Vector.rotate({
+                          x: mech.fieldRange,
+                          y: 0
+                        }, 2 * Math.PI * Math.random())))
+                        Matter.Body.setVelocity(bullet[bullet.length - 1], Vector.mult(Vector.rotate(mech.hole.unit, Math.PI / 2), 15));
+
+                      }
                       break
                     }
                   }
                 }
               }
             }
-            //mobs get pushed away
-            for (let i = 0, len = mob.length; i < len; i++) {
-              // if (!mob[i].shield && !mob[i].isShielded) {
-              if (Vector.magnitude(Vector.sub(mech.hole.pos1, mob[i].position)) < 200) {
-                const pull = Vector.mult(Vector.normalise(Vector.sub(mech.hole.pos1, mob[i].position)), -0.07)
-                Matter.Body.setVelocity(mob[i], Vector.add(mob[i].velocity, pull));
+            if (mod.isWormBullets) {
+              //teleport bullets
+              for (let i = 0, len = bullet.length; i < len; ++i) { //teleport bullets from hole1 to hole2
+                if (!bullet[i].botType && !bullet[i].isInHole) { //don't teleport bots
+                  if (Vector.magnitude(Vector.sub(mech.hole.pos1, bullet[i].position)) < mech.fieldRange) { //find if bullet is touching hole1
+                    Matter.Body.setPosition(bullet[i], Vector.add(mech.hole.pos2, Vector.sub(mech.hole.pos1, bullet[i].position)));
+                    mech.fieldRange += 5
+                    bullet[i].isInHole = true
+                  } else if (Vector.magnitude(Vector.sub(mech.hole.pos2, bullet[i].position)) < mech.fieldRange) { //find if bullet is touching hole1
+                    Matter.Body.setPosition(bullet[i], Vector.add(mech.hole.pos1, Vector.sub(mech.hole.pos2, bullet[i].position)));
+                    mech.fieldRange += 5
+                    bullet[i].isInHole = true
+                  }
+                }
               }
-              if (Vector.magnitude(Vector.sub(mech.hole.pos2, mob[i].position)) < 200) {
-                const pull = Vector.mult(Vector.normalise(Vector.sub(mech.hole.pos2, mob[i].position)), -0.07)
-                Matter.Body.setVelocity(mob[i], Vector.add(mob[i].velocity, pull));
+              // mobs get pushed away
+              for (let i = 0, len = mob.length; i < len; i++) {
+                if (Vector.magnitude(Vector.sub(mech.hole.pos1, mob[i].position)) < 200) {
+                  const pull = Vector.mult(Vector.normalise(Vector.sub(mech.hole.pos1, mob[i].position)), -0.07)
+                  Matter.Body.setVelocity(mob[i], Vector.add(mob[i].velocity, pull));
+                }
+                if (Vector.magnitude(Vector.sub(mech.hole.pos2, mob[i].position)) < 200) {
+                  const pull = Vector.mult(Vector.normalise(Vector.sub(mech.hole.pos2, mob[i].position)), -0.07)
+                  Matter.Body.setVelocity(mob[i], Vector.add(mob[i].velocity, pull));
+                }
               }
-              // }
             }
           }
 
-          if (mech.isHolding) {
-            mech.drawHold(mech.holdingTarget);
-            mech.holding();
-            mech.throwBlock();
-          } else if ((input.field && mech.fieldCDcycle < mech.cycle)) { //not hold but field button is pressed
-            // Matter.Query.ray(map, jumpSensor.position, game.mouseInGame).length === 0 ||
-            if (
-              mech.hole.isReady && !mech.holdingTarget &&
-              (
-                // Matter.Query.ray(map, player.position, game.mouseInGame).length === 0 &&
-                Matter.Query.ray(map, mech.pos, game.mouseInGame).length === 0 &&
-                Matter.Query.ray(map, mech.pos, Vector.add(Vector.mult(Vector.normalise(Vector.sub(game.mouseInGame, mech.pos)), 50), game.mouseInGame)).length === 0
-              )
+          if (input.field && mech.fieldCDcycle < mech.cycle) { //not hold but field button is pressed
+            if (mech.hole.isReady &&
+              (Matter.Query.ray(map, mech.pos, game.mouseInGame).length === 0 &&
+                Matter.Query.ray(map, mech.pos, Vector.add(Vector.mult(Vector.normalise(Vector.sub(game.mouseInGame, mech.pos)), 50), game.mouseInGame)).length === 0)
             ) {
               const sub = Vector.sub(game.mouseInGame, mech.pos)
               const mag = Vector.magnitude(sub)
               const drain = 0.06 + 0.007 * Math.sqrt(mag)
-              if (mech.energy > drain && mag > 150) {
+              if (mech.energy > drain && mag > 300) {
                 mech.energy -= drain
                 mech.hole.isReady = false;
                 mech.fieldRange = 0
@@ -2439,6 +2434,8 @@ const mech = {
                 mech.hole.pos1.y = mech.pos.y
                 mech.hole.pos2.x = player.position.x
                 mech.hole.pos2.y = player.position.y
+                mech.hole.angle = Math.atan2(sub.y, sub.x)
+                mech.hole.unit = Vector.perp(Vector.normalise(sub))
 
                 if (mod.isWormholeDamage) {
                   who = Matter.Query.ray(mob, mech.pos, game.mouseInGame, 60)
@@ -2457,14 +2454,12 @@ const mech = {
                     }
                   }
                 }
+              } else {
+                mech.grabPowerUp();
               }
+            } else {
+              mech.grabPowerUp();
             }
-            // mech.grabPowerUp();
-            // mech.lookForPickUp();  can't pick things up with this field
-            // if (mech.energy > 0.05) { //can't use shield
-            //   mech.drawField();
-            //   mech.pushMobsFacing();
-            // }
           } else if (mech.holdingTarget && mech.fieldCDcycle < mech.cycle) { //holding, but field button is released
             mech.pickUp();
           } else {
diff --git a/js/powerup.js b/js/powerup.js
index 6ec6823..ad69265 100644
--- a/js/powerup.js
+++ b/js/powerup.js
@@ -461,8 +461,8 @@ const powerUps = {
   },
   randomPowerUpCounter: 0,
   spawnBossPowerUp(x, y) { //boss spawns field and gun mod upgrades
+    // if (game.difficultyMode === 4) powerUps.spawn(x, y, "mod") //why mode gets a free mod
     powerUps.randomPowerUpCounter++;
-    if (game.difficultyMode === 4) powerUps.spawn(x, y, "mod") //why mode gets a free mod
     const chanceToFail = Math.max(level.levelsCleared, 10) * 0.1 //1 until level 10, then 1.1, 1.2, 1.3, ...
     if (Math.random() * chanceToFail < powerUps.randomPowerUpCounter) {
       powerUps.randomPowerUpCounter = 0;
@@ -470,6 +470,16 @@ const powerUps = {
     } else {
       spawnHealthAmmo()
     }
+    if (game.difficultyMode === 4) {
+      powerUps.randomPowerUpCounter++;
+      const chanceToFail = Math.max(level.levelsCleared, 10) * 0.1 //1 until level 10, then 1.1, 1.2, 1.3, ...
+      if (Math.random() * chanceToFail < powerUps.randomPowerUpCounter) {
+        powerUps.randomPowerUpCounter = 0;
+        spawnPowerUps()
+      } else {
+        spawnHealthAmmo()
+      }
+    }
 
     function spawnHealthAmmo() {
       if (mech.health < 0.65 && !mod.isEnergyHealth) {
@@ -511,7 +521,7 @@ const powerUps = {
       //bonus power ups for clearing runs in the last game
       if (level.levelsCleared === 0 && !game.isCheating) {
         for (let i = 0; i < localSettings.levelsClearedLastGame / 4 - 1; i++) {
-          powerUps.spawn(mech.pos.x, mech.pos.y, "mod", false); //spawn a mod for every 5 levels cleared in last game
+          powerUps.spawn(mech.pos.x, mech.pos.y, "mod", false); //spawn a mod for levels cleared in last game
         }
         localSettings.levelsClearedLastGame = 0 //after getting bonus power ups reset run history
         localStorage.setItem("localSettings", JSON.stringify(localSettings)); //update local storage
diff --git a/todo.txt b/todo.txt
index 639d857..e6d78ae 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,33 +1,30 @@
-some wormhole bug fixes
-wormhole mod: cosmic string - damage mobs when you teleport through them
-wormhole mod: Penrose process - overfill energy to 300% of max, with a block gets sucked into a hole
 
+mod: critical bifurcation - nail gun does 400% more damage if it hits very close to the center of a mob
+mod: supercritical fission - flechettes explode if they hit very close to the center of a mob
+
+mod: transdimensional spores - after wormholes eat blocks, they disturb spores
+mod: traversable geodesics - your bullets can go through worm holes
+
+scrap bots now only last only 30 seconds, but they have a 20% chance to spawn from a kill (was 11%)
+the difficulty should feel a bit harder after clearing the boss level
+  (a bit more more damage taken, and fewer mod drops)
 
 ************** TODO - n-gon **************
 
-set mouse 4 and 5 for gun switch
+mod - after a mob or shield dies, remaining dots look for a new nearby host
 
 add an ending to the game
   revamp the boss level, or add a new final level
-    final level requires you to kill something, not skip content
+    final level requires you to kill something
+      so skipping content is only smart if you are strong enough to beat the final boss
   around level 15
   game never ends if you have used cheats
 
-field wormhole
-  store constant info about the holes: unit, angle to save processing
-  maybe bullets should be able to enter and exit multiple times
-    or bullets shouldn't get stuck at all?
-  maybe give bullets an attraction to holes
-  player: drain energy when near a hole, does damage if no energy
-  mod: Hawking radiation: do damage, to mobs that get near the end points
-    this is good because it explains why mobs don't teleport
-  mod: extend immunity cycle after a teleport  //mech.immuneCycle = mech.cycle + 15;
-
 look for mods that could update description text with count and mod.is  information
   can only use variables that change in effect() and remove()
   this.description = `<strong>8%</strong> chance to <strong>duplicate</strong> spawned <strong>power ups</strong><br><em>chance to duplicate = ${mod.duplicateChance}</em>`
 
-mod (drones or spores) explode after 10 seconds
+mod self destruct - drones explode when they die, but they last 1/2 as long
 
 mouse event e.which is deprecated