I enjoyed the retro aesthetic with the sound effects, music, and pixel art. I also think the uppercut move was fun to do. Its practically a double jump that hurts enemies.
Combat does feel like an afterthought as the enemies don't pose much of a threat. If you expand on this, I would suggest making the enemies more challenging, or maybe have a stronger emphasis on platforming challenges, so the player could make more use of the uppercut move. Too bad you ran out of time for the ending. I thought there was going to be a boss behind the door.
Overall, nice job!