diff --git a/docs/scripting.md b/docs/scripting.md
index 7f8cd22..7e1b8b5 100644
--- a/docs/scripting.md
+++ b/docs/scripting.md
@@ -34,4 +34,7 @@ Computation takes place in turns. Each entity has functions called, if they exis
 |stop|called when the object is killed|
 |debug|use draw functions with the object's world position, during debug pass|
 |gui|draw functions in screen space, during gameplay gui pass|
-|draw|draw functions in world space|
\ No newline at end of file
+|draw|draw functions in world space|
+
+## Guidelines
+When dealing with callbacks, callback registration can include objects or functions, but not both. You should either register an object to a list that always has 'update' called on them, or you should register the object's update function as a closure over the object.
\ No newline at end of file
diff --git a/scripts/debug.js b/scripts/debug.js
index f8d5f99..f31210c 100644
--- a/scripts/debug.js
+++ b/scripts/debug.js
@@ -108,10 +108,6 @@ var Debug = {
     cmd(82, obj.body);
   },
 
-  register_call(fn, obj) {
-    Register.debug.register(fn,obj);
-  },
-
   gameobject(go) { cmd(15, go.body); },
 
   draw_bb: false,
diff --git a/scripts/editor.js b/scripts/editor.js
index 629449a..f97ce5a 100644
--- a/scripts/editor.js
+++ b/scripts/editor.js
@@ -191,7 +191,8 @@ var editor = {
     Game.play();
     Player.players[0].uncontrol(this);
     Player.players[0].control(limited_editor);
-    Register.unregister_obj(this);
+    editor.cbs.forEach(cb => cb());
+    editor.cbs = [];
     load("predbg.js");
     console.warn(`starting game with ${this.dbg_ur}`);
     editor.dbg_play = Primum.spawn(this.dbg_ur);
@@ -205,18 +206,23 @@ var editor = {
     Game.play();
     Player.players[0].uncontrol(this);
     Player.players[0].control(limited_editor);
-    Register.unregister_obj(this);
+    editor.cbs.forEach(cb=>cb());
+    editor.cbs = [];
     load("game.js");
   },
 
+  cbs: [],
+
   enter_editor() {
     Game.pause();
     Player.players[0].control(this);
     Player.players[0].uncontrol(limited_editor);
-    Register.gui.register(editor.gui, editor);
-    Register.draw.register(editor.draw, editor);
-    Debug.register_call(editor.ed_debug, editor);
-    Register.update.register(gui_controls.update, gui_controls);
+    
+    editor.cbs.push(Register.gui.register(editor.gui.bind(editor)));
+    editor.cbs.push(Register.draw.register(editor.draw.bind(editor)));
+    editor.cbs.push(Register.debug.register(editor.ed_debug.bind(editor)));
+    editor.cbs.push(Register.update.register(gui_controls.update, gui_controls));
+    
     this.desktop = Primum.spawn(ur.arena);
     Primum.rename_obj(this.desktop.toString(), "desktop");
     this.edit_level = this.desktop;
diff --git a/scripts/engine.js b/scripts/engine.js
index 4475e15..0c94410 100644
--- a/scripts/engine.js
+++ b/scripts/engine.js
@@ -81,7 +81,7 @@ var timer = {
   },
 
   kill() {
-    Register.unregister_obj(this);
+    this.end();
     this.fn = undefined;
   },
   
@@ -90,7 +90,7 @@ var timer = {
     t.time = secs;
     t.remain = secs;
     t.fn = fn;
-    Register.update.register(t.update, t);
+    t.end = Register.update.register(timer.update.bind(t));
     return function() { t.kill(); };
   },
 };
@@ -162,12 +162,7 @@ var Register = {
     });
   },
   
-  unregister_obj(obj) {
-    Register.registries.forEach(function(x) {
-      x.unregister_obj(obj);
-    });
-    Player.uncontrol(obj);
-  },
+  unregister_obj(obj) { Player.uncontrol(obj); },
 
   endofloop(fn) {
     if (!this.inloop)
@@ -186,34 +181,18 @@ var Register = {
   registries: [],
 
   add_cb(idx, name) {
-    var entries = [];
     var n = {};
+    var fns = [];
+    
     n.register = function(fn, obj) {
-      if (!obj) {
-        Log.error("Refusing to register a function without a destroying object.");
-	return;
-      }
-      entries.push({
-        fn: fn,
-	obj: obj
-      });
-    }
-
-    n.unregister = function(fn) {
-      entries = entries.filter(function(e) { return e.fn !== fn; });
-    }
-
-    n.unregister_obj = function(obj) {
-      entries = entries.filter(function(e) { return e.obj !== obj; });
-    }
-
-    n.broadcast = function(...args) {
-      entries.forEach(x => x.fn.call(x.obj, ...args));
-    }
-
-    n.clear = function() {
-      entries = [];
+      if (typeof fn !== 'function') return;
+      if (typeof obj === 'object')
+        fn = fn.bind(obj);
+      fns.push(fn);
+      return function() { fns.remove(fn); };
     }
+    n.broadcast = function(...args) { fns.forEach(x => x(...args)); }
+    n.clear = function() { fns = []; }
 
     register(idx, n.broadcast, n);
 
diff --git a/scripts/entity.js b/scripts/entity.js
index 6d1f991..94520f8 100644
--- a/scripts/entity.js
+++ b/scripts/entity.js
@@ -416,14 +416,19 @@ var gameobject = {
     this.sync();
   },
 
+  unregister() {
+    this.timers.forEach(t=>t());
+    this.timers = [];
+  },
+
   check_registers(obj) {
-    Register.unregister_obj(obj);
+    obj.unregister();
   
     if (typeof obj.update === 'function')
-      Register.update.register(obj.update, obj);
+      obj.timers.push(Register.update.register(obj.update.bind(obj)));
 
     if (typeof obj.physupdate === 'function')
-      Register.physupdate.register(obj.physupdate, obj);
+      obj.timers.push(Register.physupdate.register(obj.physupdate.bind(obj)));
 
     if (typeof obj.collide === 'function')
       obj.register_hit(obj.collide, obj);
@@ -432,13 +437,13 @@ var gameobject = {
       obj.register_separate(obj.separate, obj);
 
     if (typeof obj.draw === 'function')
-      Register.draw.register(obj.draw,obj);
+      obj.timers.push(Register.draw.register(obj.draw.bind(obj)));
 
     if (typeof obj.debug === 'function')
-      Register.debug.register(obj.debug, obj);
+      obj.timers.push(Register.debug.register(obj.debug.bind(obj)));
 
     if (typeof obj.gui === 'function')
-      Register.gui.register(obj.gui,obj);
+      obj.timers.push(Register.gui.register(obj.gui.bind(obj)));
 
     for (var k in obj) {
       if (!k.startswith("on_")) continue;
@@ -560,7 +565,7 @@ var gameobject = {
     this.__kill = true;
     
     this.timers.forEach(t => t());
-    this.timers = undefined;
+    this.timers = [];
     
     if (this.level) {
       this.level.remove_obj(this);
@@ -568,13 +573,11 @@ var gameobject = {
     }
 
     Player.do_uncontrol(this);
-    Register.unregister_obj(this);
     
     if (this.__proto__.instances)
       this.__proto__.instances.remove(this);
 
     for (var key in this.components) {
-      Register.unregister_obj(this.components[key]);
       this.components[key].kill();
       this.components[key].gameobject = undefined;
       delete this.components[key];
diff --git a/scripts/tween.js b/scripts/tween.js
index 9fe95d3..2c71260 100644
--- a/scripts/tween.js
+++ b/scripts/tween.js
@@ -173,7 +173,7 @@ var Tween = {
     
     defn.play = function() {
       if (playing) return;
-      Register.update.register(defn.fn, defn);
+      defn._end = Register.update.register(defn.fn.bind(defn));
       playing = true;
     };
     defn.restart = function() {
@@ -185,7 +185,7 @@ var Tween = {
     };
     defn.stop = function() { if (!playing) return; defn.pause(); defn.restart(); };
     defn.pause = function() {
-      Register.update.unregister(defn.fn);    
+      defn._end();
       if (!playing) return;
 
       playing = false;
diff --git a/source/engine/2dphysics.c b/source/engine/2dphysics.c
index b963cb7..ef66abe 100644
--- a/source/engine/2dphysics.c
+++ b/source/engine/2dphysics.c
@@ -625,9 +625,9 @@ static cpBool handle_collision(cpArbiter *arb, int type) {
     break;
 
   case CTYPE_SEP:
-/*    if (JS_IsObject(go->cbs.separate.obj))
+    if (JS_IsObject(go->cbs.separate.obj))
       duk_call_phys_cb(norm1, go->cbs.separate, go2, arb);
-*/
+
     break;
   }
 
diff --git a/source/engine/jsffi.c b/source/engine/jsffi.c
index 90e4ebb..28ad541 100644
--- a/source/engine/jsffi.c
+++ b/source/engine/jsffi.c
@@ -1478,11 +1478,9 @@ JSValue duk_register(JSContext *js, JSValueConst this, int argc, JSValueConst *a
     break;
 
   case 4:
-    //       unregister_obj(obj);
     break;
 
   case 5:
-    //       unregister_gui(c);
     break;
 
   case 6:
diff --git a/source/engine/particle.c b/source/engine/particle.c
index 71c46b2..2f42380 100644
--- a/source/engine/particle.c
+++ b/source/engine/particle.c
@@ -155,6 +155,7 @@ static struct par_vert pv[MAX_PARTICLES];
 void parallel_pv(emitter *e, struct scheduler *sched, struct sched_task_partition t, sched_uint thread_num)
 {
   for (int i=t.start; i < t.end; i++) {
+    if (e->particles[i].life <= 0) continue;
     particle *p = &e->particles[i];
     pv[i].pos = p->pos.xy;
     pv[i].angle = p->angle;
@@ -172,7 +173,7 @@ void emitters_draw()
     par_bind.fs.images[0] = e->texture->id;
 
     struct sched_task task;
-    scheduler_add(&sched, &task, parallel_pv, e, arrlen(e->particles), arrlen(e->particles)/SCHED_DEFAULT);
+    scheduler_add(&sched, &task, parallel_pv, e, arrlen(e->particles), arrlen(e->particles)/sched.threads_num);
     scheduler_join(&sched, &task);
     
     sg_append_buffer(par_bind.vertex_buffers[0], &(sg_range){.ptr=&pv, .size=sizeof(struct par_vert)*arrlen(e->particles)});
@@ -191,6 +192,7 @@ static HMM_Vec4 g_accel;
 void parallel_step(emitter *e, struct scheduler *shed, struct sched_task_partition t, sched_uint thread_num)
 {
   for (int i = t.end-1; i >=0; i--) {
+    if (e->particles[i].life <= 0) continue;
     if (e->gravity) 
       e->particles[i].v = HMM_AddV4(e->particles[i].v, g_accel);
     e->particles[i].v = HMM_AddV4(e->particles[i].v, HMM_MulV4F((HMM_Vec4){frand(2)-1, frand(2)-1, 0,0}, 1000*dt));
@@ -200,10 +202,10 @@ void parallel_step(emitter *e, struct scheduler *shed, struct sched_task_partiti
     e->particles[i].color = sample_sampler(&e->color, (e->life-e->particles[i].life)/e->life);
     e->particles[i].scale = e->scale;
 
-   if (e->particles[i].life <= 0)
-     arrdelswap(e->particles, i);
-   else if (query_point(e->particles[i].pos.xy))
-     arrdelswap(e->particles,i);
+//   if (e->particles[i].life <= 0)
+//     arrdelswap(e->particles, i);
+//   else if (query_point(e->particles[i].pos.xy))
+//     arrdelswap(e->particles,i);
   }
 }
 
@@ -212,7 +214,7 @@ void emitter_step(emitter *e, double mdt) {
   g_accel = HMM_MulV4F((HMM_Vec4){cpSpaceGetGravity(space).x, cpSpaceGetGravity(space).y, 0, 0}, dt);
   if (arrlen(e->particles) == 0) return;
   struct sched_task task;
-  scheduler_add(&sched, &task, parallel_step, e, arrlen(e->particles), arrlen(e->particles));
+  scheduler_add(&sched, &task, parallel_step, e, arrlen(e->particles), arrlen(e->particles)/sched.threads_num);
   scheduler_join(&sched, &task);
 
   if (!e->on) return;
diff --git a/tests/bind_v_call.js b/tests/bind_v_call.js
new file mode 100644
index 0000000..7167be8
--- /dev/null
+++ b/tests/bind_v_call.js
@@ -0,0 +1,40 @@
+var binds = [];
+var cbs = [];
+var fats = [];
+var count = 1000000;
+
+var a = {
+  n: 1
+}
+
+function test_a() {
+  this.n++;
+}
+
+var start = Date.now();
+for (var i = 0; i < count; i++) 
+  binds.push(test_a.bind(a));
+console.log(`Make bind time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++)
+  fats.push(() => test_a.call(a));
+console.log(`Make fat time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++) {
+  binds[i]();
+}
+console.log(`Bind time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++) {
+  fats[i]();
+}
+console.log(`Fat time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++)
+  test_a.call(a);
+
+console.log(`Call time: ${Date.now()-start} ms`);
diff --git a/tests/bind_v_fn.js b/tests/bind_v_fn.js
new file mode 100644
index 0000000..fc5e7d0
--- /dev/null
+++ b/tests/bind_v_fn.js
@@ -0,0 +1,24 @@
+var binds = [];
+var a = {
+  n: 1,
+  test() { this.n++; }
+};
+var count = 10000000;
+
+var start = Date.now();
+for (var i = 0; i < count; i++)
+  binds.push(a.test.bind(a));
+
+console.log(`Make bind time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++)
+  binds[i]();
+
+console.log(`Bind time: ${Date.now()-start} ms`);
+
+start = Date.now();
+for (var i = 0; i < count; i++)
+  a['test']();
+
+console.log(`Call time: ${Date.now()-start} ms`);