Meh.
Not sure why people are still losing their shit and taking everything as a personal slight.
I find that part of fandom so pathetic. I say this as a lifelong Nintendo fan.
I say it as a Metroid fan, one who is working on a career in games based entirely on my enjoyment of the Metroid games, and one that isn't happy with the way Nintendo has handled Metroid overall and who harbors serious animosity towards Other M...
... But even I think it gets to a point where it's a tad ridiculous. It can't just be an "average" or even "disappointing" game. It has to be a flaming garbage fire that openly throttles kittens, personally insults your mother, is deliberately doing everything intentionally to sabotage the franchise for everyone just to spite you, is directly responsible for the Brexit, cancelled Firefly, put Snyder in charge of the DC movies, and probably would vote for Donald Trump if it could.
It gets to a point where the complaints aren't just nitpicky, they're wildly overblown. It can't just be underwhelming or not what you like or even something you dislike (and almost nobody has actually PLAYED the full game yet). It has to look, sound, feel, and even smell bad. The box art has to be the worst ever. The cameo has to be an intentional insult. The multiplayer has to be an affront to everything Metroid stands for. The controls have to be the worst controls ever. The game has to not just be bad, not just even OTHER M bad; it has to be a game so horrendously terrible and so blitheringly incompetent and insulting that it its sheer existence is a black hole that sucks the franchise - past, present, and future - into its awful, loathsome pit of despair and misery and affront to good taste.
... Eh, I enjoyed the demo, warts and all, and I'm happy to experience something new from the Metroid universe, even if it's not the dream game I want and still ask for. I feel like giving it a fair shot, and even being okay with the game if it fails to measure up, isn't some unreasonable approach to the series (or any game, for that matter).