Fun! I couldn't beat some of the difficult levels without clipping balls through walls by setting them up against a corner in blue mode, then briefly switching to red mode while pushing it into the corner. It seems to work in basically any corner on a thin wall.
Thanks for playing! I did know about this bug, but unfortunately didn't have a ton of time to debug / fix it. To some extent I'm at the mercy of the Godot physics engine, which has a few issues (continuous collision detection seems shaky at best). I'm sure there are workarounds though, if I ever feel like continuing development of the game.