High score: 11,082.

I like how smooth it feels for a grid-based game.

Difficulty plateaus early, with fun local peaks when the blue and grey walls appear simultaneously. I like how much concentration it takes to three-shot the orange flies. Enemies and spawns don't seem to react to the player, making it easy to camp out on the screen edge, only needing to move when a blue wall appears. I'm not actually sure if the blue walls are invincible, but it's interesting how their presence means you can constantly be earning a small but steady number of points at the expense of not removing any enemies from the screen.