diff --git a/include/app/app.h b/include/app/app.h
index d1bacd4..c4b7b68 100644
--- a/include/app/app.h
+++ b/include/app/app.h
@@ -169,10 +169,9 @@ struct Scene {
     }
   }
 
-  void update_scene(uint64_t delta_time) {
+  void update_scene(mrb_value dt_val) {
     if (mrb_nil_p(update.proc))
       return;
-    mrb_value dt_val = mrb_float_value(Ruby::mrb, delta_time / 1e9);
     update.call(1, &dt_val);
   }
 
@@ -200,6 +199,8 @@ struct Scene {
         } else if (e->click_mode == ClickMode::BLOCK) {
           result.push_back(*it);
           break;
+        } else {
+          continue;
         }
       }
     }
@@ -240,6 +241,7 @@ struct App {
   std::vector<Key> released_keys;
   Vec2<float> scroll = {0, 0};
   std::string text = "";
+  Ruby::Block update;
 
   void exit() {
     running = false;
@@ -335,7 +337,12 @@ struct App {
         }
       }
 
-      scene->update_scene(dt);
+      int ai = mrb_gc_arena_save(Ruby::mrb);
+      mrb_value dt_val = mrb_float_value(Ruby::mrb, dt / 1e9);
+      update.call(1, &dt_val);
+      scene->update_scene(dt_val);
+      mrb_gc_arena_restore(Ruby::mrb, ai);
+
       scene->render(window, window.get_time());
 
       window.render();
diff --git a/include/binding/definitions.h b/include/binding/definitions.h
index 56115fd..cb16c0f 100644
--- a/include/binding/definitions.h
+++ b/include/binding/definitions.h
@@ -1629,6 +1629,22 @@ static mrb_value app_start(mrb_state *mrb, mrb_value) {
   return mrb_nil_value();
 }
 
+static mrb_value app_current_scene(mrb_state *mrb, mrb_value) {
+  uint64_t id = app_->current_scene_id;
+  if (id == UINT64_MAX)
+    return mrb_nil_value();
+  app::Scene *scene = app::scene_pool[id];
+  app::scene_pool.use(id);
+  return wrap(mrb, mrb_class_get(mrb, "Scene"), &Scene_type, id);
+}
+
+static mrb_value app_on_update(mrb_state *mrb, mrb_value) {
+  mrb_value block;
+  mrb_get_args(mrb, "&", &block);
+  app_->update.set_proc(block);
+  return mrb_nil_value();
+}
+
 static mrb_value app_switch_to(mrb_state *mrb, mrb_value) {
   mrb_value scene_val;
   mrb_get_args(mrb, "o", &scene_val);
@@ -1772,7 +1788,7 @@ inline void setup() {
   ADD_METHOD(ElementText, "eql?", element_text_equal, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "inspect", element_text_inspect, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "hash", element_text_hash, MRB_ARGS_NONE());
-  ADD_METHOD(ElementText, "on_click", element_text_on_click, MRB_ARGS_BLOCK());
+  ADD_METHOD(ElementText, "click", element_text_on_click, MRB_ARGS_BLOCK());
   ADD_METHOD(ElementText, "to_s", element_text_to_s, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "key=", element_text_key_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "key", element_text_key_get, MRB_ARGS_NONE());
@@ -1807,7 +1823,7 @@ inline void setup() {
   ADD_METHOD(ElementRect, "inspect", element_rect_inspect, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "to_s", element_rect_inspect, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "hash", element_rect_hash, MRB_ARGS_NONE());
-  ADD_METHOD(ElementRect, "on_click", element_rect_on_click, MRB_ARGS_BLOCK());
+  ADD_METHOD(ElementRect, "click", element_rect_on_click, MRB_ARGS_BLOCK());
   ADD_METHOD(ElementRect, "width=", element_rect_width_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementRect, "width", element_rect_width_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "height=", element_rect_height_set, MRB_ARGS_REQ(1));
@@ -1830,7 +1846,7 @@ inline void setup() {
   ADD_METHOD(ElementRect, "click_mode", element_rect_click_mode_get, MRB_ARGS_NONE());
 
   DEF_CLASS(ElementImage, MRB_ARGS_REQ(1) | MRB_ARGS_OPT(1));
-  ADD_METHOD(ElementImage, "on_click", element_image_on_click, MRB_ARGS_BLOCK());
+  ADD_METHOD(ElementImage, "click", element_image_on_click, MRB_ARGS_BLOCK());
   ADD_METHOD(ElementImage, "==", element_image_equal, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementImage, "eql?", element_image_equal, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementImage, "inspect", element_image_inspect, MRB_ARGS_NONE());
@@ -1862,7 +1878,7 @@ inline void setup() {
   ADD_METHOD(Scene, "<<", scene_add_element, MRB_ARGS_REQ(1));
   ADD_METHOD(Scene, "delete", scene_delete_element, MRB_ARGS_REQ(1));
   ADD_METHOD(Scene, "remove", scene_delete_element, MRB_ARGS_REQ(1));
-  ADD_METHOD(Scene, "on_update", scene_on_update, MRB_ARGS_BLOCK());
+  ADD_METHOD(Scene, "update", scene_on_update, MRB_ARGS_BLOCK());
   ADD_METHOD(Scene, "elements_at", scene_elements_at, MRB_ARGS_REQ(1));
   ADD_METHOD(Scene, "elements", scene_elements, MRB_ARGS_NONE());
 
@@ -1870,6 +1886,8 @@ inline void setup() {
   ADD_MODULE_METHOD(App, "run", app_run, MRB_ARGS_REQ(3) | MRB_ARGS_OPT(1));
   ADD_MODULE_METHOD(App, "start", app_start, MRB_ARGS_REQ(1));
   ADD_MODULE_METHOD(App, "switch_to", app_switch_to, MRB_ARGS_REQ(1));
+  ADD_MODULE_METHOD(App, "scene", app_current_scene, MRB_ARGS_NONE());
+  ADD_MODULE_METHOD(App, "update", app_on_update, MRB_ARGS_BLOCK());
   ADD_MODULE_METHOD(App, "fps=", app_fps_set, MRB_ARGS_REQ(1));
   ADD_MODULE_METHOD(App, "fps", app_fps_get, MRB_ARGS_NONE());
   ADD_MODULE_METHOD(App, "localize", app_localize, MRB_ARGS_REQ(3));
diff --git a/samples/button.rb b/samples/button.rb
index 2570367..4f2d972 100644
--- a/samples/button.rb
+++ b/samples/button.rb
@@ -12,19 +12,32 @@ bg_animation = Animation.new [bg_image1, bg_image2], fps: 5
 App.language = :en
 App.localize(:en, :btn_text, "Click %{name}!")
 
-text = ElementText.new :btn_text, default_font, 0xFFFF00, {name: "Me"}, position: {x: 50, y: 50}, z: 1, click_mode: :pass, alpha: 1
+text = ElementText.new :btn_text, default_font, 0xFFFF00, {name: "Me"}, position: {x: 50, y: 50}, z: 1, click_mode: :block, alpha: 1
 
-rect = ElementRect.new 100, 25, 0xFF0000, position: {x: 50, y: 50}, z: 0, rotation: 60, scale: { x: 1, y: 1 }, alpha: 0.4
+rect = ElementRect.new 100, 25, 0xFF0000, position: {x: 50, y: 50}, z: 0, rotation: 60, scale: { x: 1, y: 1 }, alpha: 0.8, click_mode: :block
 
 image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1, click_mode: :ignore, alpha: 1
 
 pp text, rect, image_element
 
-rect.on_click do
+end_scene = Scene.new
+end_scene << rect
+
+text.click do
+  App.switch_to end_scene
+end
+
+image_element.click do
+  pp "Image clicked"
+end
+
+rect.click do
+  pp "Rect clicked", rect.color.to_s(16)
+
   rect.color = rect.color == 0xFF0000 ?
     0x00FF00 :
     0xFF0000
-  main_scene << text unless main_scene.elements.include?(text)
+
   text.params[:name] = text.params[:name] == "Me" ?
     "You" :
     "Me"
@@ -37,7 +50,7 @@ start = Time.now
 c_ = 0.0
 c_c = 0
 
-main_scene.on_update do |delta_time|
+App.update do |delta_time|
   c_ += delta_time
   c_c += 1
 
@@ -45,7 +58,7 @@ main_scene.on_update do |delta_time|
   # commented out to avoid spamming the console, but you can uncomment to see the delta time being printed every frame
   # runs at 60fps, so you should see around 16-17ms being printed
 
-  el = main_scene.elements_at(App.mouse_position)
+  el = App.scene.elements_at(App.mouse_position)
 
   pp App.text_input if App.text_input != ""
 
@@ -68,8 +81,6 @@ main_scene << text
 main_scene << rect
 main_scene << image_element
 
-main_scene.delete(text)
-
 App.start main_scene
 
 time = Time.now - start
diff --git a/writeup/analysis.md b/writeup/analysis.md
index 1462576..3220faf 100644
--- a/writeup/analysis.md
+++ b/writeup/analysis.md
@@ -260,6 +260,8 @@ extra:
 - network interface, with a lib to work with rack backends (and generic socket api)
 - persistence store
 - rng helpers
+- tweening system
+- layout system
 
 ## Embedded scripting language choice.