I love the visualiser-style background. I could have that play in fullscreen on a secondary monitor and just be happy with playing in the corner of my eye while I work.

I think the player/enemy/bullet graphics would need to change however, as it they tend to blend in the background very easily, even with the clashing colours. Perhaps a semi transparent plane with a neutral colour between the background and the game plane would help.

The aspect ratio does create more of a small, high pressure space to play in. I would of liked to see some change in it as I play, or some mutation to that rule that adds some strategy or extra element to the game.

That background, though. Very nice!