Nice game!!
Viewing post in Bullet Chess jam comments
This base is very solid and polished.
If you pretend to expand this game, I think perhaps that you could transform it in a roguelite (bc you have everything on hands to do this), but instead of a infinit game, you would do levels with different formats and more weapons/powerups variation, and with a score table.
About the graphics, I think you could make the chess pieces a bit more clear to identify wich is what.
Hope it helps you in some way XD