Played Metroid Fusion, which to me is the last good Metroid. It's interesting to return to as its reputation at large has never really settled into any common narrative; it was a contested game in its time and remains one now. My respect for it grows with time, in how excellent it is at balancing series pillars with a genuine spirit of reinvention--it's tough for anything to manage that interaction, or as well. All the common criticisms--too linear; too directed; too talky; too artificial of setting--are all things that in the moment and in context instead turn to strengths that better the game for the branch of design it was interested in exploring and experimenting with.
The writing especially comes over well as it doesn't threaten anyone's varying mental images of Samus--she remains stoically silent, withdrawn into her own thoughts, where the only verbosity of note occurs on her part; it's significant the few times she does respond to Adam's steady stream of instructions. Internally, she has moments of wry self-reflection of her past actions and how they're mirrored in her own current circumstances and the existence of the SA-X; Metroid II lingers heavily as the turning point in this character's life, as it should, and Fusion carries those thematics forward with care. The Samus/Adam dynamic especially comes off well here as the media convention is usually to pair up a snarky, "irreverent" button-pusher along with the silent emotional recluse to maintain audience interest and facilitate reciprocal interplay, but here Adam is entirely goal-oriented, flat of affect, and Samus has nothing to say herself in most situations; the push-and-pull between an ostensible odd couple simply doesn't exist as both are unequipped to cause or react to such sparring. It's a really refreshingly matter-of-fact way to present a story that's textually contained to just these two characters.
The best things this game does in shaping its world are the assumptions it allows you to form in the beginning and then gradually doing away with the given premise. Everything about the BSL station reeks of the kind of artificiality that the primarily cavernous and interconnected series would have trained its audience to mistrust as something fundamentally undesired: wreathed in metals and manufactured materials, arranged in closed-off "levels" entered through a hub. The impression created is that the sense of Metroid play is just as superficial in the environment's wake as those spaces themselves, constructed and simulated biomes as they are. From early on though, the key aspect of Fusion's exploratory paradigm makes itself known as it's never about following a dot on the map to the destination--it's being given an objective and seeing how the environment contorts itself unexpectedly to bar one's way, and the thrilling way going "out of bounds" in the station's nominal, default layout is made integral to progression, time and time again. The built instead of formed nature of the environment takes on a particular character in this context; the feeling of dipping into maintenance shafts and auxiliary tunnels to find one's way is distinct from charting what are presented as naturally formed topography in other series games, which often take on the tone of a primal struggle against the environment itself. With Fusion, the artificiality of the setting imbues the atmosphere with a directed malice toward your intrusion in it--it's not a place where life simply occurs and reacts to Samus as the unwanted interloper, but a nest of weaponized research and cold industry.
Focusing on a cat-and-mouse survival story of near misses and scrambling escapes in a compact environment also allows the game to go further with environmental iteration than any other game in the series. Most Metroids incorporate backtracking in some way, but the common structure usually involves relegating such exploits to the player's own discretion in seeking out in fullness of what the world might contain around its peripheries; the well-trod ground players are mandated to visit more than once are dominated by connecting passages and centers of traverse on the way to the real destinations, most of which are always new. Fusion, as a set of map data on cartridge, may be slighter than other games, but its play structure demands areas to be revisited often several times before the basic sequence of the scenario is over. In so doing it doesn't risk repetition in wearing the same locales thin because as a game it's also extremely invested in a sense of environmental dynamism facilitated exactly by these repeat incursions. Creatures that lurk in the station show signs of themselves through anticipatory glimpses or simply through the wreckage left in their wake; doors may be totally trashed and the ceilings and walls ripped through to create new environmental configurations in spaces thought previously understood. An early visit to a sub-section will present the player with insect larvae, which upon departing have progressed to pupae--later still, the imago stage is reached and the location transformed in the challenges it poses and how it should be navigated. The specific spatial choreographies of the plotting ensure that these detailed environmental processes aren't overlooked, as the shifting circumstances of the rapidly deteriorating habitat slot Samus into a reactive, crisis relief unit of one, whisked from one near disaster to the next all the while carrying all the risk herself.
It must be stressed that Fusion is a hard game in the context of its series and likely outside of it too. This is mostly achieved by tuning the damage values incurred by Samus significantly higher than other games have, to a degree that it can hardly be read as accidental or undeliberate. It's then to be read in the context of a hunter being hunted via her own means, subject to the same shivering terror she once inflicted on others; the play mechanics must reflect accordingly of the newfound frailty even in a form empowered. A career athlete is still one even after life-threatening and altering sickness, and even as contrivance mandates each Metroid present the Samus-building-herself-back-up narrative again and again, Fusion is the only one where not only storytelling minutiae rationalizes the act but lends it additional gravitas in recovery from bodily trauma and reshaping oneself into something close to before, but not quite, and maybe that's for the better in the end. The harshness of surviving in Fusion builds and supports the arc of Samus taking the first, tentative steps in her new life and existence, while being haunted and punished harshly along the way by the specters of her own past. Post-traumatic adaptation is literalized in the parts of herself she regains along the way--for the first time, organically and intrinsically as part of her--by facing past nemeses and turning those experiences into strength, and the player is right there with her, in the boss fights that chart as the hardest in the series, but also the most compellingly executed to that end, as they are built on the understanding and honing of the fundamentals of Samus's abilities and do not tarry in running through their own patterns in dictating the pace of the encounters. They are as madcap or strategic, cumbersome or elegant as anyone wants them to be, and none of it's accomplished through anything but confidence in the player's own internalization of the tools afforded to them; they are there for both them and Samus to take control.
The miracle of Metroid Fusion is that it's a game that in its time ushered in the return of a series that had previously hit its definitive high and then disappeared for a time that by objective reckoning was lengthy, but in the less tapped-in age decades past felt exponentially longer of an absence. When it did return, it did not lean on a sure formula, as the previous game had even then been canonized as a trailblazer. Instead, it made changes and took risks: the protagonist fundamentally altered visually and existentially; the game structure fashioned into a new modular script; series iconography like Ridley and the Chozo in the (mercifully) most reduced roles they would ever have. The reason why I increasingly value the game can be found in these characteristics that define it, as the last moment before the image of the series settled into a set of interchangeable aesthetics, design goals and repeated iconography for all time, sustained by a loop of still-notable absences and a resetting just-give-me-something-please return-to-form rhetoric. This was the time that Metroid went away and came back changed, and it might as well have been an evolutionary dead-end that it did so.