Pokemon works because it plays off what I like to refer to as the Elder Scrolls timeline, where each Elder Scrolls game is the same concept in the same world, but with a different region of that world, at a different time period. That world, like in Pokemon, is unspoken about, almost taboo perhaps, as no insight at all is ever given to its size, is it a planet? is it, just a plane of existence? Is it purgatory? (I'm looking at you, Lost) Who the **** knows? It's hard to argue with the continuity of the story when you don't know exactly what the hell is going on. Zelda, they play off the folklore type thing, that while Link is technically Link in every game, he's not the "same" Link, rather a nearly identical Elvish boy "reborn" into that area to fight the "reborn" evil with the "reborn" princess, the same spiritual figures bound to eternally fulfill a prophecy, in that magical mythical world, it works, because, well it's magic and you can defy the laws of space and time. Metroid, however, suffers from the lost timeline syndrome, where it can't seem to figure out when in the hell it is, for all we know, Metroid could be taking place in our area of the universe 3,000 years from now, or in the time of the fucking Crusades in some other dimension of space, not to mention, where in proximity to the Lylat system Samus Aran is, is Star Fox part of a UN of galactic federation? Are Metroids or X parasites going to infest Dinosaur Planet? Not to mention on top of that, unlike all these other storyline methodologies, Samus Aran exists in the same time period, as a mortal woman, easily starting out in her 20's to 30's. Most of these events are written so as they ran consecutively to each other, one almost always beginning from the aftermath of a previous mission. That's not to say that one couldn't "wormhole" the timeline and rewrite and reorganize events without disturbing the continuity of the timeline, or perhaps even, eradicate an entire title and replace it with key details to fill in the blanks. Considering Nintendo pulled a Star Wars and wrote three of the last titles first, and then came back and re-wrote three prequels, the Prime games, made Fusion, this way end game, somewhere in the middle of those, and then shoved Other M in between them, with a ton of continuity between Super and Other M, and virtually none between Other M and Fusion. The only thing in that game is Adam, and like I just said, Fusion came out long before Other M, so nobody really knew who Adam was, with the exception of the explanation it gave, and it was satisfying, until OTHER M. So if we theoretically do that Men In Black thing and erase everyone's minds of Other M, we could technically just never insert that title, place her on SR388 after the final eradication of the Metroids (Super) and still technically leave a ton of open ended areas to go after Fusion, since she gets her powers back, and there's never any real burned bridges in the series, considering how many times the Metroids were "eradicated" and how uncontained the Metroid universe is, like all their other worlds, it's very easy to build off of. It's incredible how in depth a video game's storyline can really be if you want to dig deep enough into it.