Metroid Prime
Weary, exhausted, and more than likely chafing from that heavy armor she has to lumber around, heroic bounty hunter Samus Aran defeats her rather persistant arch-nemesis, Ridley, and proceeds to the depths of Talon IV's Impact Crater. Following a rather irritating section involving damn-near indestructible Metroids and a vertical climb to a door located at the top of the room, she enters and finds an empty cavern with what appears to be a strange organic blob hanging from the ceiling.
Could it be? Mother Brain? No, of course not. Why does everyone say that? What's wrong with you? Mother Brain was a gigantic brain sitting in a jar surrounded by missile launchers and cheerio guns. This doesn't even remotely resemble that. And it's an entirely different planet to boot. You think Mother Brain just decided to take a vacation to sunny Talon IV and hang out in a cave? Alone? Are you high?
No, this is something else. Something worse maybe. Perhaps something familiar. This is your Metroid on drugs. Or rather, phazon, which certain pirate logs tell me is pretty potent stuff. This is a Metroid that has dwelled in a cave that's infested with radioactive goo, and mutated into something... else.
The creature unravels itself and drops from the ceiling, revealing its true form. And size. Yikes. Turns out that harmless looking blob is actually some kind of giant alien spider. Possibly crab. Samus scans the monstrous being for weak points in the hope of inflicting massive damage, and finds her target. She lets loose with all she has at the creature's face, but it seems to have found itself some space pirate technology somewhere down the line, and can alter its exoskeleton to block all types of incoming shots except one. Those jolly little pirates were kind enough to make their armoring technology color-coded. When purple, use the wave beam. When white, use ice. When red, plasma. Easy.
Or not. Metroid Prime isn't quite content to sit around and let you blast it while it changes to every color in the rainbow. It has quite a few attacks of its own. Energy bubbles, phazon blasts, grappling beams, and when all-else fails nothing beats a good old-fashioned tackle. Samus has to be quick to dodge the onslaught of attacks, but fortunately she's had plenty of practice.
Several rounds back and forth force the giant metroid deeper into the maze of caverns that dwell beneath Talon IV's surface. After four or five battles with the creature, it limps off to a final cave, its armor explodes and you finally get to see its true form.
So, it is a Metroid afterall! The floating semi-transparent mass of tentacles looks down on Samus with contempt, and begins to bombard her with phazon attacks as it gracefully zips around the room. After dodging and weaving out the way of enough energy beams, Prime creates a pool of phazon and vanishes. Samus scans all visor modes to find the creature, but it seems that her trusty weapons no longer have any effect. Fortunately the phazon suit that Samus acquired earlier in her mission seems to have the uncanny ability to channel the newly-created phazon lying around in the cavern. She stands in a pool of the radioactive goo and sends the phazon energy straight through her arm cannon into the monster.
The battle persists, but Prime is out of ideas. It resorts to calling on its fellow Metroid bretheren to assist, and Samus is suddenly attacked by a swarm of Hunter and Fission Metroids. No match for a well placed power bomb, of course, but it's a distraction, and distractions can be rather unfortunate when fighting for your life against giant alien jellyfish monsters.
In its dying breath, Prime lashes out with its tentacles and attempts to grab Samus and take her down with it. In the struggle it somehow manages to tear off Samus' phazon suit, while leaving the gravity suit completely intact. Samus recovers and watches as the creature explodes into a puddle of Metroid goo.
Mission Comp-PSYCHE! Self-destruct sequence activated! The crater begins to crumble and Samus makes an epic, inspiring, off-camera escape to the surface, calling her ship to pick her up.
After a hard battle won, and the impact crater in ruin, Samus hops aboard her ship, removes her helmet and gazes upon the destruction before her. Now that's what you call fan service. Mission Complete.
