diff --git a/source/engine/2dphysics.c b/source/engine/2dphysics.c
index 727c3eb..50c1628 100644
--- a/source/engine/2dphysics.c
+++ b/source/engine/2dphysics.c
@@ -464,8 +464,11 @@ void phys2d_reindex_body(cpBody *body) {
     cpSpaceReindexShapesForBody(space, body);
 }
 
+void register_collide(void *sym) {
 
-static cpBool s7_phys_cb_begin(cpArbiter *arb, cpSpace *space, void *data) {
+}
+
+static cpBool script_phys_cb_begin(cpArbiter *arb, cpSpace *space, void *data) {
     struct gameobject *go = data;
 
     cpBody *body1;
@@ -474,9 +477,19 @@ static cpBool s7_phys_cb_begin(cpArbiter *arb, cpSpace *space, void *data) {
 
     struct gameobject *g2 = cpBodyGetUserData(body2);
 
-    //script_call_sym_args(go->cbs->begin, s7_make_integer(s7, g2->editor.id));
-    //s7_call(s7, go->cbs->begin, s7_list(s7, 2, s7_make_integer(s7, g2->editor.id), cpvec2s7(cpArbiterGetNormal(arb))));
+    duk_push_heapptr(duk, go->cbs.begin.fn);
+    duk_push_heapptr(duk, go->cbs.begin.obj);
 
+    int obj = duk_push_object(duk);
+
+    vect2duk(cpArbiterGetNormal(arb));
+    duk_put_prop_literal(duk, obj, "normal");
+
+    duk_push_int(duk, g2->editor.id);
+    duk_put_prop_literal(duk, obj, "hit");
+
+    duk_call_method(duk, 1);
+    duk_pop(duk);
 
     return 1;
 }
@@ -494,18 +507,15 @@ static void s7_phys_cb_separate(cpArbiter *Arb, cpSpace *space, void *data) {
     //script_call_sym(go->cbs->separate);
 }
 
-void phys2d_add_handler_type(int cmd, struct gameobject *go, void *cb) {
+void phys2d_add_handler_type(int cmd, struct gameobject *go, struct callee c) {
     cpCollisionHandler *handler = cpSpaceAddWildcardHandler(space, go);
 
-    if (!go->cbs)
-        go->cbs = malloc(sizeof(*go->cbs));
-
     handler->userData = go;
 
     switch (cmd) {
         case 0:
-            //handler->beginFunc = s7_phys_cb_begin;
-            //go->cbs->begin = cb;
+            handler->beginFunc = script_phys_cb_begin;
+            go->cbs.begin = c;
             break;
 
         case 1:
diff --git a/source/engine/2dphysics.h b/source/engine/2dphysics.h
index 9855509..0267cb6 100644
--- a/source/engine/2dphysics.h
+++ b/source/engine/2dphysics.h
@@ -2,6 +2,7 @@
 #define TWODPHYSICS_H
 
 #include <chipmunk/chipmunk.h>
+#include "script.h"
 
 struct gameobject;
 
@@ -10,11 +11,6 @@ extern float phys2d_gravity;
 extern int physOn;
 extern cpSpace *space;
 
-struct phys_cbs {
-    void *begin;
-    void *separate;
-};
-
 struct phys2d_shape {
     cpShape *shape;
     struct gameobject *go;
@@ -98,7 +94,13 @@ void edge_gui(struct phys2d_edge *edge);
 void phys2d_init();
 void phys2d_update(float deltaT);
 
-void phys2d_add_handler_type(int cmd, struct gameobject *go,  void *cb);
+struct phys_cbs {
+    struct callee begin;
+    struct callee separate;
+};
+
+void phys2d_add_handler_type(int cmd, struct gameobject *go,  struct callee c);
+void register_collide(void *sym);
 void phys2d_set_gravity(cpVect v);
 
 void shape_gui(struct phys2d_shape *shape);
diff --git a/source/engine/ffi.c b/source/engine/ffi.c
index 9094e02..97a1af2 100644
--- a/source/engine/ffi.c
+++ b/source/engine/ffi.c
@@ -22,8 +22,6 @@ cpVect duk2vec2(duk_context *duk, int p) {
     duk_get_prop_index(duk, p, 0);
     pos.x = duk_to_number(duk, -1);
     duk_get_prop_index(duk, p, 1);
-
-
     pos.y = duk_to_number(duk, -1);
 
     return pos;
@@ -70,7 +68,7 @@ duk_ret_t duk_cmd(duk_context *duk) {
         break;
 
        case 2:
-         register_gui(duk_get_heapptr(duk, 1));
+
          break;
 
        case 3:
@@ -97,11 +95,61 @@ duk_ret_t duk_cmd(duk_context *duk) {
          phys2d_set_gravity(duk2vec2(duk, 1));
          break;
 
+       case 9:
+
+         break;
+
+       case 10:
+
+         break;
+
+       case 11:
+
+         break;
+
     }
 
     return 0;
 }
 
+duk_ret_t duk_register(duk_context *duk) {
+    int cmd = duk_to_int(duk, 0);
+    void *fn = duk_get_heapptr(duk, 1);
+    void *obj = duk_get_heapptr(duk, 2);
+
+   struct callee c = {fn, obj};
+
+   switch(cmd) {
+     case 0:
+       register_update(c);
+       break;
+
+     case 1:
+       register_physics(c);
+       break;
+
+     case 2:
+       register_gui(c);
+       break;
+     }
+
+   return 0;
+}
+
+duk_ret_t duk_register_collide(duk_context *duk) {
+    int cmd = duk_to_int(duk, 0);
+    void *fn = duk_get_heapptr(duk, 1);
+    void *obj = duk_get_heapptr(duk, 2);
+    int go = duk_get_int(duk, 3);
+
+    struct callee c = {fn, obj};
+    YughInfo("Registering ...");
+
+    phys2d_add_handler_type(0, get_gameobject_from_id(go), c);
+
+    return 0;
+}
+
 duk_ret_t duk_sys_cmd(duk_context *duk) {
     int cmd = duk_to_int(duk, 0);
 
@@ -151,24 +199,6 @@ duk_ret_t duk_sys_cmd(duk_context *duk) {
     return 0;
 }
 
-duk_ret_t duk_register(duk_context *duk) {
-    int cmd = duk_to_int(duk, 0);
-    void *obj = duk_get_heapptr(duk, 1);
-    void *fn = duk_get_heapptr(duk, 2);
-
-    switch (cmd) {
-      case 0:
-        register_update(obj, fn);
-        break;
-
-      case 1:
-        register_physics(obj, fn);
-        break;
-    }
-
-    return 0;
-}
-
 duk_ret_t duk_make_gameobject(duk_context *duk) {
     int g = MakeGameobject();
     struct gameobject *go = get_gameobject_from_id(g);
@@ -251,6 +281,8 @@ duk_ret_t duk_q_body(duk_context *duk) {
     int q = duk_to_int(duk, 0);
     struct gameobject *go = get_gameobject_from_id(duk_to_int(duk, 1));
 
+    if (!go) return 0;
+
     switch(q) {
         case 0:
           duk_push_int(duk, cpBodyGetType(go->body));
@@ -263,6 +295,18 @@ duk_ret_t duk_q_body(duk_context *duk) {
         case 2:
           duk_push_number(duk, cpBodyGetAngle(go->body));
           return 1;
+
+        case 3:
+          vect2duk(cpBodyGetVelocity(go->body));
+          return 1;
+
+        case 4:
+          duk_push_number(duk, cpBodyGetAngularVelocity(go->body));
+          return 1;
+
+        case 5:
+          duk_push_number(duk, cpBodyGetMass(go->body));
+          return 1;
     }
 
     return 0;
@@ -284,8 +328,8 @@ duk_ret_t duk_make_box2d(duk_context *duk) {
 }
 
 duk_ret_t duk_make_circle2d(duk_context *duk) {
-  int go = duk_to_int(duk, 0);
-  double radius = duk2vec2(duk, 1);
+   int go = duk_to_int(duk, 0);
+  double radius = duk_to_number(duk, 1);
   cpVect offset = duk2vec2(duk, 2);
 
     struct phys2d_circle *circle = Make2DCircle(get_gameobject_from_id(go));
@@ -345,7 +389,6 @@ void ffi_load()
     DUK_FUNC(make_gameobject, 7);
     DUK_FUNC(set_body, 3);
     DUK_FUNC(q_body, 2);
-    DUK_FUNC(register, 3);
     DUK_FUNC(sys_cmd, 1);
     DUK_FUNC(win_make, 3);
 
@@ -353,6 +396,8 @@ void ffi_load()
     DUK_FUNC(make_box2d, 3);
     DUK_FUNC(make_circle2d, 3);
     DUK_FUNC(cmd, 2);
+    DUK_FUNC(register, 3);
+    DUK_FUNC(register_collide, 4);
 
     DUK_FUNC(gui_text, 3);
     DUK_FUNC(gui_img, 2);
diff --git a/source/engine/gameobject.c b/source/engine/gameobject.c
index 05bde0e..0be6049 100644
--- a/source/engine/gameobject.c
+++ b/source/engine/gameobject.c
@@ -21,7 +21,8 @@ const int nameBuf[MAXNAME] = { 0 };
 const int prefabNameBuf[MAXNAME] = { 0 };
 
 struct gameobject *get_gameobject_from_id(int id)
-{
+{  if (id < 0) return NULL;
+
     return &gameobjects[id];
 }
 
@@ -54,7 +55,7 @@ static void gameobject_setpickcolor(struct gameobject *go)
 
 int MakeGameobject()
 {
-    if (gameobjects == NULL) arrsetcap(gameobjects, 5000);
+    if (gameobjects == NULL) arrsetcap(gameobjects, 50);
 
     struct gameobject go = {
         .editor.id = arrlen(gameobjects),
diff --git a/source/engine/gameobject.h b/source/engine/gameobject.h
index 75c5e76..27317df 100644
--- a/source/engine/gameobject.h
+++ b/source/engine/gameobject.h
@@ -24,10 +24,6 @@ struct editor {
     char rootPrefabName[MAXNAME];
 };
 
-struct go_temp {
-    struct phys_cbs phys_cbs;
-};
-
 struct gameobject {
     cpBodyType bodytype;
     float scale;
@@ -38,7 +34,7 @@ struct gameobject {
     int flipy;
     cpBody *body;
     struct component *components;
-    struct phys_cbs *cbs;
+    struct phys_cbs cbs;
     struct editor editor;
 };
 
diff --git a/source/engine/script.c b/source/engine/script.c
index ff09442..804a797 100644
--- a/source/engine/script.c
+++ b/source/engine/script.c
@@ -111,50 +111,52 @@ void script_call_sym_args(void *sym, void *args)
     //s7_call(s7, sym, s7_cons(s7, args, s7_nil(s7)));
 }
 
-struct obupdate {
-    void *obj;
-    void *sym;
-};
 
-struct obupdate *updates = NULL;
-struct obupdate *physics = NULL;
-void **guis = NULL;
 
-void register_update(void *obj, void *sym) {
-    struct obupdate ob = {obj, sym};
-    arrput(updates, ob);
+struct callee *updates = NULL;
+struct callee *physics = NULL;
+struct callee *guis = NULL;
+
+void register_update(struct callee c) {
+    arrput(updates, c);
+}
+
+void register_gui(struct callee c) {
+    arrput(guis, c);
+}
+
+void register_physics(struct callee c) {
+    arrput(physics, c);
+}
+
+void call_callee(struct callee c) {
+    duk_push_heapptr(duk, c.fn);
+    duk_push_heapptr(duk, c.obj);
+    duk_call_method(duk, 0);
+    duk_pop(duk);
+}
+
+void callee_dbl(struct callee c, double d) {
+    duk_push_heapptr(duk, c.fn);
+    duk_push_heapptr(duk, c.obj);
+    duk_push_number(duk, d);
+    duk_call_method(duk, 1);
+    duk_pop(duk);
 }
 
 void call_updates(double dt) {
     for (int i = 0; i < arrlen(updates); i++) {
-        duk_push_heapptr(duk, updates[i].obj);
-        duk_push_heapptr(duk, updates[i].sym);
-        duk_push_number(duk, dt);
-        duk_call_prop(duk, -3, 1);
-        duk_pop_2(duk);
+        callee_dbl(updates[i], dt);
     }
 }
 
-void register_gui(void *sym) {
-    arrput(guis, sym);
-}
-
 void call_gui() {
     for (int i = 0; i < arrlen(guis); i++)
-        script_call_sym(guis[i]);
-}
-
-void register_physics(void *obj, void *sym) {
-    struct obupdate ob = {obj, sym};
-    arrput(physics, ob);
+        call_callee(guis[i]);
 }
 
 void call_physics(double dt) {
     for (int i = 0; i < arrlen(physics); i++) {
-        duk_push_heapptr(duk, physics[i].obj);
-        duk_push_heapptr(duk, physics[i].sym);
-        duk_push_number(duk, dt);
-        duk_call_prop(duk, -3, 1);
-        duk_pop_2(duk);
+        callee_dbl(updates[i], dt);
     }
 }
diff --git a/source/engine/script.h b/source/engine/script.h
index 13bac60..411e646 100644
--- a/source/engine/script.h
+++ b/source/engine/script.h
@@ -6,6 +6,12 @@
 
 extern duk_context *duk;
 
+
+struct callee {
+  void *fn;
+  void *obj;
+};
+
 void script_init();
 void script_run(const char *script);
 int script_dofile(const char *file);
@@ -18,13 +24,13 @@ void script_call_sym_args(void *sym, void *args);
 int script_has_sym(void *sym);
 void script_eval_w_env(const char *s, void *env);
 
-void register_update(void *obj, void *sym);
+void register_update(struct callee c);
 void call_updates(double dt);
 
-void register_gui(void *sym);
+void register_gui(struct callee c);
 void call_gui();
 
-void register_physics(void *obj, void *sym);
+void register_physics(struct callee c);
 void call_physics(double dt);
 
 duk_idx_t vec2duk(cpVect v);