diff --git a/js/index.js b/js/index.js
index e87e868..bfafe9a 100644
--- a/js/index.js
+++ b/js/index.js
@@ -2,17 +2,6 @@
 /* TODO:  *******************************************
 *****************************************************
 
-general gun power ups
-  +explosion radius
-  +dmg
-  life steal
-  ice bullets  (reduce mob velocity on dmg)
-  +bullet size
-  get bonus ammo / reduced ammo use
-  +reduced cs on fire  (faster fire rate)
-  orbiting orb fires at random targets
-    missiles at random targets
-
 have mob acceleration and look frequency scale with difficulty level
   this will speed up the responses of later mobs
   this should provide a feeling of difficulty without inflating the life of mobs
@@ -46,15 +35,11 @@ game mechanics
     low friction ground
     bouncy ground
 
- give each foot a sensor to check for ground collisions
-  	feet with not go into the ground even on slanted ground
- 	this might be not worth it, but it might look really cool
-
 track foot positions with velocity better as the player walks/crouch/runs
 
 add bullet on damage effects
 	effects could:
-		add to the array mod.do new mob behaviors
+		add to the array mob.do new mob behaviors
 			add a damage over time
 			add a freeze
 		change mob traits
@@ -75,10 +60,6 @@ add bullet on damage effects
 		remove standing on player actions
 			replace with check if player feet are in an area.
 
-unused ideas
-passive: walk through blocks  (difficult to implement)
-
-
 
 
 
diff --git a/js/level.js b/js/level.js
index 43cacc7..061f594 100644
--- a/js/level.js
+++ b/js/level.js
@@ -15,7 +15,7 @@ const level = {
       document.title = "n-gon";
       this.intro(); //starting level
       // b.giveGuns(0) // set a starting gun for testing
-      // mech.fieldUpgrades[5]() //give a field power up for testing
+      mech.fieldUpgrades[6]() //give a field power up for testing
       // game.levelsCleared = 3; //for testing to simulate possible mobs spawns
       // this.bosses();
       // this.testingMap();
diff --git a/js/mobs.js b/js/mobs.js
index baab3b7..bb66987 100644
--- a/js/mobs.js
+++ b/js/mobs.js
@@ -98,10 +98,12 @@ const mobs = {
       },
       seePlayerFreq: 20 + Math.round(Math.random() * 20), //how often NPC checks to see where player is, lower numbers have better vision
       foundPlayer() {
-        this.locatePlayer();
-        if (!this.seePlayer.yes) {
-          this.alertNearByMobs();
-          this.seePlayer.yes = true;
+        if (!mech.isStealth) {
+          this.locatePlayer();
+          if (!this.seePlayer.yes) {
+            this.alertNearByMobs();
+            this.seePlayer.yes = true;
+          }
         }
       },
       lostPlayer() {
diff --git a/js/player.js b/js/player.js
index c6c787a..846b144 100644
--- a/js/player.js
+++ b/js/player.js
@@ -470,6 +470,7 @@ const mech = {
     index: 0
   },
   isHolding: false,
+  isStealth: false,
   throwCharge: 0,
   fireCDcycle: 0,
   fieldCDcycle: 0,
@@ -493,6 +494,7 @@ const mech = {
     this.fieldMeter = 1;
     this.fieldRegen = 0.0015;
     this.fieldCDcycle = 0;
+    this.isStealth = false;
     this.holdingMassScale = 0.5;
     this.throwChargeRate = 2;
     this.throwChargeMax = 50;
@@ -1035,6 +1037,49 @@ const mech = {
         mech.drawFieldMeter()
       }
     },
+    () => {
+      mech.fieldMode = 6;
+      game.makeTextLog("<strong style='font-size:30px;'>Metamaterial Refractive Optics</strong><br> (left mouse or space bar) <p>localized invisibility field</p>", 1000);
+      mech.setHoldDefaults();
+      mech.fieldArc = 1; //field covers full 360 degrees
+      mech.calculateFieldThreshold();
+
+      mech.hold = function () {
+        mech.isStealth = false //isStealth is checked in mob foundPlayer()
+
+        if (mech.isHolding) {
+          mech.drawHold(mech.holdingTarget);
+          mech.holding();
+          mech.throw();
+        } else if ((keys[32] || game.mouseDownRight) && mech.fieldCDcycle < game.cycle) {
+          const DRAIN = 0.0015 //mech.fieldRegen = 0.0015
+          if (mech.fieldMeter > DRAIN) {
+            mech.fieldMeter -= DRAIN;
+            mech.isStealth = true //isStealth is checked in mob foundPlayer() 
+
+            //draw stealth field
+            // ctx.fillStyle = "rgba(255,255,155,0.9)";
+            // ctx.fillStyle = "rgba(255,255,255,1)";
+            ctx.fill();
+            ctx.beginPath();
+            ctx.arc(mech.pos.x, mech.pos.y + 25, 110, 0, 2 * Math.PI);
+            ctx.globalCompositeOperation = "destination-in";
+            ctx.fill();
+            ctx.globalCompositeOperation = "source-over";
+
+            mech.grabPowerUp();
+            mech.lookForPickUp();
+          } else {
+            mech.fieldCDcycle = game.cycle + 120;
+          }
+        } else if (mech.holdingTarget && mech.fireCDcycle < game.cycle) { //holding, but field button is released
+          mech.pickUp();
+        } else {
+          mech.holdingTarget = null; //clears holding target (this is so you only pick up right after the field button is released and a hold target exists)
+        }
+        mech.drawFieldMeter()
+      }
+    },
     // () => {
     //   mech.fieldMode = 1;
     //   game.makeTextLog("<h2>Time Dilation Field</h2><br><strong>active ability:</strong> hold left and right mouse to slow time<br><strong>passive bonus:</strong> +field regeneration", 1000); //<br><strong>passive bonus:</strong> can phase through blocks