Breakneck pacing through linear design cleverly made to feel open, combined with the themes of lost agency and the powers one serves betraying them, which juxtaposes excellently by finally facing off with the pinnacle of power Samus used to be - now a horrific weapon to be feared and avoided. I love how naked it all makes you feel, Samus has her powers literally surgically removed from her body, your superiors withhold upgrades from you and lord complete command of your exploration, the new Fusion Suit follows a very bare, muscular system aesthetic, and that's the point.
Your adversary is the SA-X, a fully suited and booted walking sun, it practically glides through the station like a hot knife through butter - but despite inferior firepower and four layers of Federation protocol to sieve through, you've got the one thing it lacks. Wits.

If I could change one thing, it'd be for the opening act to be far less verbose and slow. If I could change a second thing, it'd be to make power bombs actually useful against bosses.