The game is very well done, impressive even for being a Jam game, I really liked the art style and gameplay, and its very well polished. Only critique i have is that the game might be a little bit too hard (it might be because i am bad at it), since the screen gets too cluttered with enemies and projectiles, maybe moving the camera a little bit more far away could help, or making enemies a little bit weaker (less HP), not sure.
But overall, its really cool and well done, just maybe too hard in parts, congratulations on the game!

Also, really cool cover art, makes me think a little bit of Samurai Jack.