Nightmare Fuel: The Game Over screen, where you watch the player character instantly mutate into one of the aliens, and then jump towards you at the screen.
Fridge Brilliance: The Game Over screen will show up even if you win - the brilliance is that you were probably a Zombie Infectee from the first time you got hit. The rest of the game is trying to take down the bastards before you turn. Or else it's a hint at the hidden Kronn Hunter mode, implying that even in the normal mode, you were a Kronn the whole time, and upon death or victory, you shed your human disguise.
Special Effects Failure: Upon closer inspection, you can see that the aliens all explode in the exact same manner when you shoot them. Also the characters you see in-game, human and alien will sometimes flicker, making their presence as sprites rather obvious.
