Metriod needs a new great game to be relevant again as a big Nintendo IP. They need the level of Metroid Prime and off course its sales.
It's good news that Nintendo clearly know it also.

Bolded, as that's what I got from the video. And yeah, if the fundament is shit, don't try to built something on top of it as it can only become shit, too

I don’t think I’ve ever wanted to know about a gaming situation more desperately than this.

I’m aching to know what Retro has been doing for five years, and what went wrong with Metroid Prime 4.

Well, the big rumour/'leak' last year was that a Star Fox racing game was in development and potentially scheduled for 2019. Kotaku ran the most detailed report, which suggested a second project had been in development for even longer - but that this second project also enountered severe difficulties and likely would be cancelled.

Given Retro weren't given Prime 4 in the first instance, I can only assume that in 2017, Retro Studios were unavailable for Metroid Prime 4 development duty - suggesting they had at least one project on the go. It's highly likely that Retro have spent at least some of the last five years working on a project which has been cancelled, as rumours and reports suggested in late spring/early summer last year. Rumours suggest we've got one of two scenarios:

1) At least one major project (Star Fox GP or the unnamed title) at Retro was cancelled last year, leaving them free to take over Metroid Prime 4 development.

2) Star Fox GP is nearly finished, the second project was either cancelled early in 2018 or never existed, and now they are taking on Prime 4 development.

I think the second one is the right scenarios. Btw it'sad to hear so bad news, but i'm also glad to see Nintendo doing this, they preferred to inform us than keep it secret

Sucks but I'd rather it be done over and right than it be done badly.

Get out a remaster of the original trilogy in the meantime.

If that´s the case then what the hell have they been working on for the past 5 years?...that supposed Star Fox racing game?...but then was it also in development hell?

Well if our expectations weren't high enough for this game already, Nintendo has certainly put themselves in a situation that the only escape from is a perfect game. It's good that they went and found Retro then. I'm not sure any other studio announcement would have been met with such positivity and understanding.

Some people are saying that they just shouldn't have announced the game so early. I for one am happy that they did. Whether they announced it or not people would have been asking for a Metroid title. But more importantly, and this they addressed in the video, they saw exactly how rabid the core Nintendo fanbase is for this series, regardless of Other M. Just look up Metroid Prime 4 reveal videos on YouTube and make sure to turn your volumes down first. Pretty ridiculous. So Nintendo knows that in order to make good on those expectations they'll need to get the best of the best. I also wonder considering that they had to go and probably beg Retro to work on the project, and given that Switch sales are very high, and given the perceived hype for this title, that they might give Retro a very robust budget, moreso than in past installments. They know they have to stick this landing and they know the expectations that have been built by Breath of the Wild, Mario Odyssey, and Smash, and they know they need to deliver a Switch-level of improvement and flair.

I'm super bummed I won't be seeing this game soon. I had tempered my expectations adequately as far as release date, and today I wake up to find out that those expectations need to be further adjusted. But I'm ok, and I feel like most of us are. 2019 is going to be a great year, 2020 probably has some pretty amazing announcements just around the corner, and sometime around E3 2021 we'll see the first teaser for Prime. At least now we can stop worrying whether it'll show for the next few years.

Oh...and hopefully this does mean that whatever Retro has been working on for the past 4 years is going gold. One thing I can guarantee, though, is that it wasn't Metroid. Haha.

Restarting from scratch? hmmm.... this means 2022-2023 atleast right? Oh well.

The soonest you ll see this is 2022, imo.

This might end up being a launch title for the switch successor.