Pretty cool top-down shooter! As others have mentioned, the shop in this game is absolutely GOATed, and Ironmouse in the main menu looks really nice! Also love how Bubi is implemented as an AOE attack, adds a bit more strategy to the shooting.
My main complaint with the game is that the enemies don't scale as fast as you do, so it doesn't feel like the game presents any challenge.
And since you asked to mention the bugs (sorry if i sound nitpicky...): yep, the game breaks when you exit to the menu and then re-enter, I suspect some Awake or Start function doesn't get called, because the info menu on the left isn't initialized and is filled with junk, and the enemies don't start to spawn. Other than that, I noticed that if you kill an enemy just before it attacks, the attack still gets executed afterwards.
All in all, really nice entry! Hope you'll polish it after the voting period ends.