WOW! Astonishing game, really well game. Everything in this game is really well put together and its so fun to play. I love the mechanic of the stage getting smaller, really nice use of the theme. The visuals especially are really cool, you should be proud.
One suggestion would be to disable the ability for players to pick an upgrade for a second or something when it first appears or have a small animation as the menu shows up. I accidently clicked an upgrade not knowing it was gonna show up because I was clicking the fire button so much haha! Minor thing though. Overall, excellent game!