Very fun playing through this one :)
The level design was very enjoyable, and I thought it was really neat when you began to remix the mechanics and combine them (for example, having to avoid the mushrooms when trying to swim to the bottom).
The art seemed to vary pretty drastically, in some cases it looked super polished and in other spots it felt a little tough for me to understand exactly what I was seeing. On a similar note, the first level or two has the battery HUD on a black background and I couldn't tell if the battery was full or not until seeing it against a white background. I think a white outline around the battery HUD would make it readable for any situation!
Overall, nice work, and well done for such a quick jam! I would love to play an expanded version as this was fun and has a lot of promise for more levels :D