you've created a cool atmosphere! i like hanging around in it!
there are some points that i think will make it a better experience: you can arrange walls better to help the flow of jumping around (i bumped a lot on my way!), and levels are too dark, maybe if you increase the contrast of colors it will be better! and in the end, try to decrease your game size! 100MB is too much for a simple platformer game.
good job! and keep on improving!