diff --git a/config.js b/config.js
index e505c97..d5517b0 100644
--- a/config.js
+++ b/config.js
@@ -140,7 +140,7 @@ var paddle = gameobject.clone("paddle", {
   },
 
   collide(hit) {
-    if (!hit.obj.from === 'ball') return;
+    if (!(hit.obj.from === 'ball')) return;
     var xdiff = hit.pos.x - this.pos.x;
     if (Math.sign(xdiff) === Math.sign(hit.obj.velocity)) return;
     var oldvel = hit.obj.velocity;
@@ -159,10 +159,11 @@ gameobject.clone("upgrade_drop", {
 
   start() {
     this.collider.radius = 15;
+    this.collider.sensor = true;
   },
 
   draw() {
-    Debug.box(this.pos, [this.size,this.size], Color.white);  
+    Shape.circle(this.pos,this.size/3,Color.white);
   },
 
   collide(hit) {
@@ -170,7 +171,7 @@ gameobject.clone("upgrade_drop", {
       return;
 
     this.upgrade();
-    Register.postphys_cbs.push(() => { this.kill(); });
+    this.kill();
   },
 
   update(dt) {
diff --git a/game.js b/game.js
index 745fc20..1ddf91c 100644
--- a/game.js
+++ b/game.js
@@ -6,11 +6,11 @@ sim_start();
 World.loadfile("lvl1.lvl");
 
 function spawnball() {
-var bb = World.spawn(gameobjects['ball']);
-bb.pos = bb.pos.add([50,0]);
-bb.pos.y += 200;
-bb.draw_layer = 3;
-bb.tag = 'ball';
+  var bb = World.spawn(gameobjects['ball']);
+  bb.pos = bb.pos.add([50,0]);
+  bb.pos.y += 200;
+  bb.draw_layer = 3;
+  bb.tag = 'ball';
 }
 
 function spawn_powerup(pos, fn) {
@@ -20,15 +20,10 @@ function spawn_powerup(pos, fn) {
   p.upgrade = fn;
 }
 
-var Game = {
-  grow() {
-
-  },
-};
-
 spawn_powerup([0,300], () => { 
-var up = World.spawn(gameobjects['upgrade_drop']);
-up.pos = [0,300];
+  for (var i = 0; i < 10; i++)
+    spawnball();
+});
 
 function lostlife() {
   lives--;
@@ -37,11 +32,11 @@ function lostlife() {
 
 spawnball();
 
+
 var f = World.spawn(gameobjects['edge2d']);
 f.edge2d.cpoints = Geometry.box(lvlwidth,lvlheight);
 f.edge2d.thickness = 10;
 f.mass = 50;
-//f.phys = 0;
 
 var killbox = World.spawn(gameobjects['polygon2d']);
 
@@ -49,12 +44,11 @@ killbox.polygon2d.points = Geometry.box(lvlwidth,30);
 killbox.pos = [0,-lvlheight/2];
 killbox.polygon2d.sensor = true;
 killbox.register_hit(hit => {
-  if (hit.obj.tag === 'ball') {
-    Register.postphys_cbs.push(() => {
-      hit.obj.kill();
-      lostlife();
-    });
-  }
+  if (hit.obj.tag !== 'ball')
+    return;
+
+  hit.obj.kill();
+  lostlife();
 }, this);
 
 //Sound.play("start.wav");