Metroid Fusion takes the vast exploration of Super and splits it into smaller chunks - levels are largely sectioned off from each other and while each is kind of a mini metroidvania map in itself, the game is very much a linear progression that holds your hand on where to go. Combined with a revamped control feel and heavier emphasis on combat Fusion can sometimes feel more like an action game with some exploration than a "true" metroidvania
Now, that sounds pretty bad right. But here's the thing: on its own merits Fusion is REALLY fucking good. That previously mentioned revamped control feel? To accompany the newly placed emphasis on action Samus is no longer a floaty tank but an agile glass cannon with the dev team's work on Wario Land 4 helping inform how snappy Fusion feels. The emphasis on action means lots of boss fights and generally they're very dynamic and exciting, with figuring out how to beat them being half the battle and actually executing your strategy being a decent challenge. Fusion also looks fantastic, especially when using color correction to match how it would look on the original non-backlit LCD. The sound is slightly disappointingly just average overall, the GBA's limitations hurt some of the tracks and some of the sound effects aren't as satisfying as they are in Super.
Good game

I'm a total sucker for time travel stories and this has a couple neat ideas and moments but the surrounding story and writing is mostly just ok.
The gameplay is in a similar boat, lots of interesting ideas but wrapped in a kind of mediocre package. The move to Uncharted-esque climbing and "puzzle solving" to fill time between battles feels like a swing and a miss and it feels like too much of the challenge comes from limited access to your power set, whether through the slow cooldown timers or more annoyingly enemies that can just negate them. There's also a big lack of polish to the technical side, the art direction and cutscenes can be very good looking yet at the same time massive bugs can crop up, like a weird stutter to the in-engine cutscenes or one trigger not activating forcing me to restart the chapter, and it's clearly the first game made on this engine with some very spotty reconstruction artifacts (even at the higher res on Series X) and screen space effects.
It's also all tied to a live action "show" played in between acts that has the vibe of a D-tier NBC drama. Bless Lance Reddick he is acting circles around Aidan Gillen's awful American accent here.
It's a massively important game in Remedy's history, laying the technical foundation for Control and Alan Wake 2, and overall worth playing as there is still fun and some great bits to be had here, but it's Remedy's weakest game by a large margin imo