Alien Storm/Nightmare Fuel


 * The enemies are nasty looking, and you spend the last level inside one (the Sega Genesis version also does away with a good deal of the humor of the arcade version, and changes the mood to be more serious in tone)!
 * The special mention is possibly the Creeper enemies. They don't look scary in Regular Mode, but in First-Person Mode, that's the only way for the player how the Creepers' nasty face actually look like.
 * And Giant Creeper in Arcade version, dear God, they are Mook Maker! That's a quite escalation from Genesis version because in Genesis version, they are completely harmless.