I feel like it's bold of a sequel to at least sort of admit it can never be "Super Metroid", so Fusion here doesn't even try to be. It refines the movement to give Samus a little more finesse and the ability to be a little more mobile and makes things like wall jumps and space jump a little more consistent, but to make up for it, it cranks up the difficulty a lot. Samus in Super is a freight train of pain, Samus in Fusion is comparably VERY fragile, which really works for the horror-lite angle of this game. Even the health and ammo drops are trying to kill you in this game.

Speaking of horror, SA-X is a very interesting antagonist, getting to essentially be Samus in her prime but as a much colder, animal-like killer that you absolutely do not stand a chance against for most of the game. In execution, she turns up at set moments in the story and only one chase sequence is forced and is even all that difficult, so SA-X just isn't that scary to me. Though maybe I'd sing a different tune there had I played this when I was a kid and this game was new.

It's comparably very linear to other Metroids, very little being able to be sequence-broken, but it serves multiple story purposes, both in how there's a very set sequence of events to go through in the story and how it's reflective of the Federation keeping Samus under their thumb. It's claustrophobia but from a completely different angle, which then makes it gratifying when you get Screw Attack and can finally freely explore the station on your whim. To which they include a lot of tricky puzzles to practice. This does inevitably mean it has a "lap around the world" issue unlike Super, but I'm not sure how else they could've done it.