First, you play as Samus Aran's daughter. Let's call her Sophie. Hold back your rage, I address alternatives at the end. Second, Sophie fights the Galactic Federation, which has become corrupted. Of crucial importance is that the corruption is not phazon, or metroids, or SA-X. It's just the GFed becoming power hungry after finally eliminating the space pirates. They start aggressively "colonizing" other populated worlds.
The game would start with Sophie, on some GFed assignment that seems to be a good idea at first. Maybe they tell you that this planet was making weapons for the space pirates, and you have to go destroy the arms factories. But gradually the realization dawns that the mission is tantamount to slaughtering innocents — they weren't helping the pirates willingly, their economy is in ruins, and you're just killing refugees. And the GFed commanders knew it. Here's the part I have no idea how to implement: I want to make it as much as possible the player's choice of when to rebel and turn against the GFed people. Prime 3 had this amazing nonstandard game over mechanic where if you let your phazon overload go for too long, you turn completely corrupted. Maybe something like this could happen, where if you continue to participate in the atrocities being visited on innocents by the GFed, you get an ending scenario of the Galactic Empire being ruled by you (think Bioshock's 'evil' ending.), and then it spits you back out at some suitable checkpoint. The real feat of game design here would be giving the player the option to turn and fire at the GFed troops without giving away that that's what you're supposed to do.
So you've turned against the Galactic Federation. The reveal mission serves as a tutorial of sorts, where you get to use all of the usual toys - missiles, super missiles, plasma beam, wave beam, ice attacks, scanning hacks, spider ball, et cetera. But then when you turn, the GFed commander who's there seems to relish the opportunity to take you down. They even anticipated you'd do something like this, and so he climbs into his own armored suit and knocks the stuffing out of you. All your toys are useless — remember that the GFed has been studying Samus' suit for a long time. He knocks you down and leaves you for dead.
On recovery, there's a cutscene of Sophie going through the suit menu and deactivating all those weapon modules. They're dead weight, you see. And now she needs to be faster than ever. (Note: I'm just really proud of having come up with a depowering plot device that's different and makes sense.) Your ship was taken, too. One of the locals, though, is now sympathetic to your cause and gives you a generic shuttle.
From here you have to work your way through GFed military installations. Piece by piece, bit by bit, you fight the new armed forces and learn how to defeat their new weaponry and defenses. Your ever-adaptable Chozo suit incorporates their technology. This is a fantastic opportunity to invent some brand new toys to play with (Please comment with ideas!). Also, and maybe this is just because I'm a pacifist, I'd want Sophie to not kill any of the GFed grunts, just the high-level military commanders who are actively directing the Bad Things. So maybe a stun weapon is the first thing you unlock. The big bosses (and I mean physically large), would be terrifying war machines the GFed is planning to deploy. The low-level environmental enemies could be nonsentient droids, turrets, and other security systems.
There are a couple different ways I see the game ending. One is that, unlike her mother, Sophie is more of a people person. She gains allies during her trek, to be sure, but at the end she's the new (temporary!) leader of the Galactic Federation. The other is that she's quite like her mother, very much a lone wolf type. Not really a public leader. So the story ends with her allies within the GFed taking over and restoring a peaceful society. In either case, at the end of the story, with victory obtained and the galaxy once again at peace, Sophie's allies thank her for all she has done.
Sophie removes her helmet, and says, "No problem." And she's black.
It's not a subtle allegory. But I'm okay with that.
Okay, so now let's talk alternatives. Because despite how much I want Sophie as the player character, it's not obvious to me that Samus Aran would choose to have a child. Option one is to go the Amanda Ripley/Lin Beifong route and simply have an unspecified father. Option two, given the advanced tech of the setting, is to have Aran Jr be a clone of some kind. This simplifies Samus's story but feels like it cheapens who the daughter is, as a separate character. Option three is don't use Samus' daughter at all, but have it be an older Samus who comes out of retirement. Then at the very end, she passes the suit onto her daughter. Personally I'm leaning towards option one.
Edit: I just realized I didn't really account for the ending of Metroid Fusion, wherein Samus and the GFed are already not on the best of terms. My game idea could either build directly off of that, or happen decades later after that particular conflict was resolved.
NEXT TIME: A trope-conscious MMO.
x-posted to vgse.weebly.com.