"EVEN" Star Fox?

Oh god. Metroid fans can be so spoiled sometimes. They get a series with countless stellar games and entries every so often, and as soon as they don't hear about it for 5 years after one poor title they're already off complaining. Please. Star Fox hasn't had a single good game in over 17 years and it's been 8 years since the latest installment, and that's for a franchise that typically sells more units than Metroid.

You want to play a good Metroid game? You got Metroid, Metroid 2, Metroid 3, Metroid 4, Metroid Prime, Metroid Prime 2, Metroid Prime 3, Metroid Zero Mission, Metroid Prime Hunters... a Star Fox fan has to keep replaying the 1-hour long Star Fox 64 over and over and over. So stop your moaning, please.

(damn, I had no idea I was so touchy about that)
Anyways, I'm still sure we're getting some Metroid games in a couple of years.

Star Fox SNES sold more than the best selling Metroid game and Star Fox 64 sold over a million more than that. Adventures was poorly received by the fans for being a huge departure from the series and a big disappointment overall, and it still sold better than every Metroid game apart from the first one and Prime. It's no big surprise that sales would have declined after disappointing entries, and Assault being another weak game it's no wonder it sold even less, but it still sold better than a few Metroid games at that, and the only Star Fox remake is about to outsell the both Metroid remakes in a console with a far smaller userbase than either the GBA or Wii had. The only Star Fox game to not outsell a Metroid one is Command, which was the third disappointment in a row, had a terrible artstyle, no voice acting, touch controls and an atrocious story.

So please don't say Metroid sells more. Star Fox has more wide recognition and appeal and it's games tend to sell more than Metroid when they're good, and even when they're bad they can sometimes outsell stellar Metroid entries, which also obviously cost way more to develop because of them usually being more ambitious titles.

Star Fox is an on-rails shooter. So yeah, it's fucking awesosome

"my favorite franchise's games didn't sell as well in SNES and didn't even exist on N64 so they don't count"

Please.

So I guess Sonic also sells more than Metroid.

Oh wait, Lost World Wii U/3DS and Sonic Boom Wii U/3DS all tanked. And Sonic Colors sold less than Metroid Prime 3. 

Please, Star Fox was revolutionary on the SNES, that's why it sold a lot. On rail shooters aren't relevant anymore these days. 

so? Star Fox SNES still sold more than any Metroid game

It was one of the first (if not the first) 3D game.

Unless you think a game can still sell 4 million units on the account of being in 3D the new Star Fox won't sell anywhere near 4 million. Hence the example is not relevant in the slightest. 

and why another Metroid is relevant if it's in the same boat? Because I really doubt that another Metroid would sell more than 2mil on Wii U

Nobody is claiming it will sell that much. It won't need to sell 2 million to beat Star Fox Wii U in sales.