This is pretty cool, I really like the concept, the visuals and particles!
Some minor things: It wasn't that clear that you had to shoot the enemies into the corners, figured it out on the second try though and the camera probably didn't have to move with the player on a map this small.
Other than that you obviously could have added some more different enemies and power-ups and maybe some temporary obstacles for more varied gameplay, but can't really expect that from a jam game! Good job!
(Also, I really like your game page, gotta take some inspiration from that)