This was fun! Although it seems like a fairly standard shoot 'em up at first glance, it keeps introducing new enemies to keep things challenging, and really forces you to think about what you need to upgrade to survive longer. The extra touches, like the changeable palette and frame rate, really sell the game and give it a more polished feel.
I got a score of 37,538 points on my first try. I got overwhelmed on the first level with the splitting enemies; they force you to stay busy with them for a long time, and a missile would always spawn while I was trying to shoot them and hit my elevator.