How complex can Metroid really be? It's basically an extended riff on Ridley Scott's Alien. An outer space bounty hunter puts on an Iron Man suit, travels to exotic planets, and hunts extraterrestrial parasites. That's all there is to it, right? Wrong. Metroid lore is just as twisty and complicated as any of Zebes' underground mazes, so follow our guide closely. When things get this wild, it's easy to get lost.