Very sharp looking game! The variety of enemies and how you have to deal with them is really cool, as well as the upgrades. My laptop had a bit of slowdown. Might be interesting to see how it runs in an exe as well.
One strange bug I ran into is at the beginning when says "Click to Start", sometimes after the game loads, the direction that the player fires is different than the crosshair position, but if I leave my mouse absolutely still after clicking to start, it's usually pretty centered.