this game is very cute. I found myself mixing up which direction to swap my powerups a lot, but that's kinda just what happens when I'm not used to the game yet
I was thinking, if you're having trouble fitting buttons in on Pico8, have you ever tried using O or X as a modifier key? it might have been interesting to hold X down and press left or right for the pap, and up/down for the other two.. maybe that's too complicated for this game, but in the future if you're ever hurting for keys that might help