Nice game! Art is great and sound effects complimentary, music enjoyable too.
Your attacks could use a visual touch up, perhaps making the fist big and white at the front of the attack, to easier judge range and area. The dark fist on dark background makes it hard to figure out.
Platforming feels good, not too challenging of jumps, but it may be better to front-load instant death areas. Fighting through several enemies and collecting things, to die instantly near the end of a level and repeat all you've already done, doesn't feel great.