As you already mentioned, there are indeed a few bugs that make it hard to complete the game!
For what I was able to play though, here's some thoughts:
- Audio would add lots of character to your game, a cool soundtrack and some punches SFX would really increase the enjoyment of your game
- The punch animation is perhaps a bit too long
- It would have been nice to see the power increase at a faster rate, it would conveyed the idea for your game better!
Besides this, nice job on completing a game in 48 hours! The visuals and core mechanic were nice!