The art is good. I like the art.
The audio is also good, but the background music only plays in the left ear, and that bothers me bit. If it weren't for that, the audio would be near perfect. A little variation in the sounds would also be nice, but that might be reaching for a three hour jam.
The gameplay actually reminds me a lot of Super Mario Bros. The enemy killing gives me strong goomba vibes. I like it! I also like the way the mechanics are introduced kind of slowly to ease you in. That said, the lack of checkpoints is annoying and the hitboxes are a little jank. It also gets a little bit repetitive.
All in all, while it has some things that I think could be fixed, I do like the art style, I do like the potential for the gameplay, and I would like the audio if it played in both ears. Good luck!