I would agree that the negativity online is bit over blown. However when it comes to gameplay and animations, what we have seen so far does look very dated. It's not necessarily a bad thing either, if what people want is more Prime they certainly have it. Seemingly anyway.
As far as I'm concerned this is par the course for a Nintendo trailer. We first see what we generally know and love. It's very safe. Months later just before release we find out a major hook and gameplay loops that have half of us screaming in delight.
The arm cannon and morph ball gameplay look to play and animate exactly as we remember. Granted there are additions shown. It looks like she can dash backward and controlling shots like the Beatle from Skyward Sword will definitely change things up.
Add that to the somewhat slippery and jittery animations of the 4 armed enemies along with the relatively closed off environments I can see why people are disappointed for now. After 16 years I would just say it looks a little too similar to what came before.
It's less than 3 minutes of footage from what's obvious the opening part of the game, from what's also an unfinished build of the game. For all we know once Samus gets that new Ladybug suit, she gains a ton of new abilities that radically change the way she controls. Some thing with the environments. The early part is smaller and more closed off, then suddenly you get some giant open area's that are much bigger than anything in the original trilogy.
This is what makes much the negativity beyond pathetic and stupid. It's nothing more than a teaser trailer for a game that none of us even know what the release date is yet. This is like when people seriously thought Mario Odyssey was going to be an auto-runner based on 3 seconds of footage, or how many we're complaining that Breath of the Wild wouldn't have any towns or NPC's to interact with because none of the early trailers showed them. Even the original Metroid Prime had people calling it a generic FPS when it was first revealed with many saying they had no faith it could possibly turn out any good.
You'd think people would have learn by now after being proven wrong for the one billionth time, but nope, it's the same **** every single time. It's one thing for people to want to see more footage, but when many are already declaring this a soul less rehash of Prime 1 based on less then 3 minutes of footage, that is beyond ridiculous. Especially when we'll more then likely get more information on the game in the Switch 2 Direct, which is less then a week away.