First off, kudos for implementing a full turn based combat system for a game jam!
I'll note that there could be a bit more feedback. Battles end so abruptly that it's a bit jarring, and there could be a little bit more game juice for both hitting an enemy and getting hit. The final battle is very easy to cheese by staying at the top of the screen during the final barrage, since the pellets very rarely spawned higher up.
Overall, cute little game.