Actually, it's not bad. I do have some suggestions, tho:
- Use both the WASD keys and the arrow keys. That way, it's more comfortable for people to play. I'm having trouble with my left hand, and really could've benefoted from using hte arrow keys.
-Use the space bar to start/restart. It's easier than picking up the mouse and then going back to the keys to play.
-The power ups need to stay in longer. If it's a bullet hell game, often you just plain can't get to the side of the screen that the powerup is going to.
-Speed up the Game Over screen and let me play! Having the option to restart straight from the Game Over screen and bypassing the menu is a big help. Pressing space to restart is convenient.