On the page you mention that you didn't have time for visuals, focusing on gameplay - I felt that there was so much great visual juice packed in, I'd love to see what you come up with given more time!
Game was fun, I liked that enemies start off slow and increase their speed as your score/time played increases! My one issue gameplay-wise was that since drops that would increase my power bar weren't guarenteed, I felt I was being punished for wasting power moving if it wasn't to pick up a power cell. As such my strategy was to remain completely still and wait for enemies to get close, before firing and grabbing any power cells/powerups. It's a small topic at the end of the day, and very much personal to me - it could be a mechanic others playing really liked!