Refactors (#114)

* Update Engine.cpp

* fix

* Add Actors

* Refactor

* Update Game.cpp

* Refactors as per review

src/engine/courses/RainbowRoad.cpp

@@ -107,8 +107,6 @@ void RainbowRoad::SpawnActors() {
     spawn_all_item_boxes((struct ActorSpawnData*)LOAD_ASSET_RAW(d_course_rainbow_road_item_box_spawns));
 }
 
-void RainbowRoad::Init() {}
-
 void RainbowRoad::InitClouds() {
     init_stars(this->Props.Clouds);
 }