A quick question, you mentioned slopes being expensive, is this just in scenes they are in, while you're using them, or does it affect the whole project regardless of if the scene has slopes in
It will effect any platformer scene type (but not other scenes). Even if a scene doesn't have a slope tile, the player still needs to do an extra check each frame for potential slope collisions. It isn't a big hit in color mode, but DMG is already pretty tight for CPU usage.