Found a glitch. At the 3rd boss (the ship/aircraft carrier one), I died from the boss's minions after having destroyed the boss himself. I was then able to "resume from boss" in the shop, and it put me directly against the next boss (the flying gattling gun one). Alas, nothing worked, I couldn't shoot, and his bullets weren't harming me.
 "Swarm Simulator: Evolution"){kind=icon}
 "Ruthless Pandas"){kind=icon}
 "Into Space 2"){kind=icon}