We now have a movement mechanic!
I remembered this old idea I had but never got around to actually using in a full game. It's reversed and tweaked a bit here, but it's still based on the same idea. The original concept was that gravity was flipped 90° in the nonexistent Z direction to swap between a platformer and top-down game, but I decided I didn't like falling off the background walls and dying so I just made it so that you can grab onto walls. It's pretty fun to use, and I think it could make for some interesting level design. It also didn't give me a million bugs while I was coding it which was nice. Now that this is done I can go on to make levels... finally.