I think this is a really cool start for a game. There are a few small changes you could make the would make a world of difference in how fun the game is:
- The screen shake is way overkill. It makes it kinda disorienting to play.
- The emissive lights look really cool, but I think you might have taken it a step overboard. It's very difficult to see where enemies are and where their bullets are. I think it also hits performance kinda hard.
I think if you work on those two things, you've got a really fun game on your hands.