As we know, Metroid fans collective shit was lost at this year's E3 when Nintendo unveiled not one, but TWO Metroid games currently in development. Metroid: Samus Returns for the Nintendo 3DS and Metroid Prime 4 for the Nintendo Switch. With this, Metroid is back with a bang! But the big question mark is, is it back for good? There is only one factor that can answer that question, that factor is the commercial success of these two games. Since Prime 4 isn't coming anytime soon and it will be quite a while before we even see a trailer of that game let alone gameplay footage, let's focus our attention to the other Metroid game that was announced, Metroid: Samus Returns, a remake of Metroid II: Return of Samus, coming out in 3 months on September 15th. This is a 2D Metroid game and thus, it is only right that we compare it to sales of 2D Metroid games in the past to see just what standards it needs to live up to.
So without further ado:
Metroid (NES) - 2.73 million
Metroid II: Return of Samus (GB) - 1.76 million
Metroid Fusion (GBA) - 1.68 million
Super Metroid (SNES) - 1.42 million
Metroid: Zero Mission (GBA) - 0.84 million
Metroid: Samus Returns (3DS) - ???

Nintendo is giving Metroid another chance here, and this cannot be stressed enough, these games NEED to sell if the series is to continue and grow. They NEED to. Samus Returns will be the first test for the series' future. So how  much do you think it will sell lifetime and just how important do you think the performance of these games are to the future of the franchise?

Yep. It needs to sell. Nintendo is testing - maybe for a last time - on how well 2D or 3D Metroid can sell.

Metroid Prime could become an expensive game on their part so they are putting in the effort on all fields.

I would say Metroid: Samus returns could at least sell 1.5 to 2 m. If more, then the better. But it should be able to scrape together a minimum of 1.5 to 2 m sales.

You can usually vaguely predict it based on how much attention the trailers get. This one has got a lot more attention than I think people might've expected.

Pretty close to 2 million views at this point. Which probably makes it the 2nd most popular Nintendo trailer of E3.

1-2 million, budget title for the switch would of worked better but eh.

750k-1m is the option I went for.

I don't think it'll be a big seller. So I'm predicting 500k for its sales.

I think it will 1.5 million. Less than Fusion, more than Zero Mission. People are Metroid thirsty, so it will sell decently.

I really don't know. 
I have already said goodbye to 3DS. It seems like a mistake to make this a 3DS game at this point, with the Switch on the market.

Metroid is popular in a certain sub-group of Nintendo fans that you never meet in real life but seem to be loud on the Internet. Most of that group don't seem to have any interest in handhelds. The only group remaining where 3DS is actually still alive are the Pokemon fans, and if Gameboy is any indication, Pokemon games could sell well on 3DS until 2035, but few others will pick it up for anything.

That said, this game looks a lot more interesting than the FPS Metroids, for one thing, it looks more lively, less empty. So that may appeal to a lot of new fans. It might not, Metroid is not that popular of a franchise despite its fans trying to convince everyone it is.

I can say, if it was on Switch, I'd buy it, even if the graphics were identical.

Anything between 80K and 1.2M wouldn't surprise me in the slightest.

It makes me very sad to admit that it probably won't light up any sales charts. All this waiting for a new Metroid, and all that will happen is we Metroid fans will once again be reminded that though vocal, we are the minority.

If it isn't too expensive and if Nintendo gives it enough attention, 1.3 million.