Samus controls fluidly, the game flows quickly, the environment changes constantly to limit the enormous maze of ZDR down to mostly manageable chunks, refill stations are frequent enough to eliminate all need for grinding, enemies are appropriately punishing and bosses are fast and tough.
All of Samus' animations in and out of cutscenes are insanely satisfying.
EMMI sections are very effective at reversing Samus' unstoppable momentum and forcing you into a survival oriented mindset, which at first is a very fun change of pace but as the game progresses this becomes flat out frustrating. The margin for error is necessarily thin, but needing to spend so much time tracking through EMMI zones is not satisfying. Thematically it feels like a mostly pointless reimagining of the SA-X: yes, the EMMI are better executed, but this hunter has been hunted before, for the same reason even.
Burenia is a beautiful zone with fantastic music and atmosphere. Ghavoran is visually memorable. Artaria's music is unique. The rest of ZDR is unfortunately very forgettable.

Adam turning heel for the second time in a row is a really weak plot twist, and it's even worse this time since the "all of your successes were actually my plan all along" thing is very last minute and never foreshadowed this time. The final scene of the X parasites saving Samus also falls totally flat and comes across as cheap strangeness for the sake of intrigue rather than any kind of considered plot point. It's as if Metroid villains need to always have some kind of mysterious emotional side now just because the ending of Super was so memorable. It didn't work in Fusion, so they really shouldn't have tried it again here.
Teleporters and strangely placed elevators make separation between zones feel extremely arbitrary as if the machines were primarily solutions to technical limitations or just attempts to make the map harder to understand. Not the game world, the map. I wonder if the game would be more enjoyable with no teleporters.
It's extremely clear that Mercury Steam's first priorities were to create satisfying gameplay that marries Fusion's storytelling ability with a huge expansion on Super's exploration, and to make Samus feel like a badass. They are wildly successful on this front and I don't think anyone will disagree. Dread's artwork is also very high quality. It's a shame that everything else falls flat, particularly the storyline. Metroid 1's story was cut and dry like a typical 80's sci fi game, Metroid 2's twist was subversive and casted doubt on our actions up to that point, Super's twist tosses morality into the mix with a surprisingly emotional scene, Fusion fully explores Samus' change from a ruthless killing machine to something more reserved and empathetic in an extremely interesting role reversal and confirms our doubts about the authority she's been working under up to this point, and Dread... shows us a few Chozo? Gives us Doom Slayer Samus? What was the goal for the story? The reveal that she's "a Metroid" is only exciting for its mechanical implications of a new superpower, because in all other regards she's been a Metroid for 20 years. Why is she working for the Federation again after they directly backstabbed her and proved that they're just as dangerous as the space pirates? What are we supposed to take away from this, the fact that the Chozo are morally questionable? We've been pretty sure about that since we found out that the Metroids were created by them, so like... Is this just what they thought would be a worthy capstone to the story of Metroids? C'mon, guys, this is not even as interesting as Prime 1's plot.
The final moments absolutely stray into Dragon Ball Z fanfic territoy. But for as showy and shallow and ridiculous as it is, seeing Samus finally let out the violence is extremely gratifying.