The art and music are top notch, consistent retro style, good quality as well.
The physics tho, is very wonky, I'd suggest spending more time on fine tuning the physics and player control than the amount of content. I'm amazed you can make so much content in just 4 days, but if the player don't have the patience to complete all the content, all the effort is wasted right?
Cool concept, great visual and audio, and the sheer amount of content, I can see how much effort you've poured into it. Good job :D