haha, this is rad. good unification of mechanics and aesthetics. it would be neat if the game sped up a bit over time, as things never seemed to get too dangerous.
Thanks - I made an update this afternoon that increases difficulty over time. Eventually, the enemies spawn twice as fast, and the warning time for lasers gets cut in half.
The enemies also explode into stardust now, but that doesn't really affect the difficulty one way or the other.