Really solid mechanics and aesthetic for the timeframe. The running and jumping feel pretty good, main points of improvement come in time saving and such. A larger hitbox on the keys would make them easier to pick up (especially the one or two you have to really jump for), a sound when a key appears so you don't miss it in the debris, and maybe just a little bit of an indicator of where to look (or not look).
Small animation thing for the running, if the arms lead the legs by a bit it'll look more convincing
Big points for the main menu leading right into the game, that's always so fun
Also being able to immediately adjust the volume is very welcome