diff --git a/src/game.cc b/src/game.cc
index 6522250..ff14e51 100644
--- a/src/game.cc
+++ b/src/game.cc
@@ -23,3 +23,8 @@ void Game::update() {
 void Game::draw() { screen_stack->draw(); }
 
 void Game::clear_screens() { screen_stack->clear_screens(); }
+
+void Game::clear_and_push_trunner() {
+  screen_stack->clear_screens();
+  screen_stack->push_constructing_screen<TRunnerScreen>();
+}
diff --git a/src/game.h b/src/game.h
index 1d6c764..1a50778 100644
--- a/src/game.h
+++ b/src/game.h
@@ -23,6 +23,7 @@ class Game {
   void draw();
 
   void clear_screens();
+  void clear_and_push_trunner();
 
  private:
   ScreenStack::Ptr screen_stack;
diff --git a/src/main.cc b/src/main.cc
index a0287e2..9548455 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -16,7 +16,7 @@
 
 #ifdef __EMSCRIPTEN__
 
-extern Game *global_game_ptr = nullptr;
+extern Game *global_game_ptr;
 
 extern "C" {
 
@@ -37,6 +37,14 @@ int EMSCRIPTEN_KEEPALIVE clear_all_screens() {
   return 1;
 }
 
+int EMSCRIPTEN_KEEPALIVE clear_and_push_trunner() {
+  if (global_game_ptr) {
+    global_game_ptr->clear_and_push_trunner();
+    return 0;
+  }
+  return 1;
+}
+
 }  // extern "C"
 #endif
 
diff --git a/wasm_build/custom_shell.html b/wasm_build/custom_shell.html
index 2bf70b1..7166eb9 100644
--- a/wasm_build/custom_shell.html
+++ b/wasm_build/custom_shell.html
@@ -60,7 +60,10 @@
         console.log("onerror: " + event);
       };
       function demo0_clear_all_screens() {
-        Module.ccall('clear_all_screens', 'number', [], []);
+        return Module.ccall('clear_all_screens', 'number', [], []);
+      };
+      function demo0_clear_and_push_trunner() {
+        return Module.ccall('clear_and_push_trunner', 'number', [], []);
       };
     </script>
     {{{ SCRIPT }}}