Nice job on your jam entry! 🎮😊
For something made in around 15 to 20 hours, this is a solid little game with a clear idea, a complete game loop and a good small scope.
I liked the 1v1 boss duel concept. The background track also worked well and gave the game a nice atmosphere 🎵, although I think I recognized the music, so just be a little careful with copyright when using existing tracks in future projects. Officially, copyrighted music should only be used if you have permission, a license, or the proper rights to use it.
A few constructive tips for next time: some SFX would help a lot, especially for shooting, hits, shield blocks, damage, and arena danger. Also, because this needs two local players, not everyone in a game jam will have someone nearby to play with. For future jams, you could maybe add a simple single-player mode, AI opponent, or training/test mode so more people can fully try and rate the game.
As mentioned in another comment too, I did not really notice the knockback while playing. Maybe it was there, but it could be made a bit clearer or stronger. Upgrades could also be really cool to add in a future update or in another version of the game.
The theme is definitely present, although it could perhaps be pushed a little more so the you are the boss battle feeling comes through even stronger. ✅
Overall, I had fun to play. Good work. Keep going like this! 🚀💪