They could have done Super Metroid once again and no one would have blamed them, instead they decided to take everything from Super Metroid and flip it on its head to make a game that, while keeping to some extent the same game loop, feels completely different: you're guided instead of moving at your own pace, you're underpowered instead of overpowered, you're running instead of hunting... Ultimately, this game shines when those restrictions are removed and you're left alone in a hostile environment, and getting back on track is up to you. The SA-X is one of the best "story through gameplay" mechanics I've ever seen in a game, it just wraps up the whole thing for me.