In japan, Otome games.

Since I dont really like platformers I always feel like there are way too many on the market, lol.

But in all seriousness though, it should be between FPS and Open World.

I feel like there have been enough indie Metroidvania titles to qualify it, but you can never have too many of those and this cannot be oversaturated.

So FPS, because it'd please me greatly to see this genre die out.

FPS as of now.

FPS games, followed by sandbox (open-world) games.

First person shooters, of course.

FPS, TPS, WRPG & JRPG are equally oversaturated games nowadays, i would consider open-world as a genre, but it's just a mega map design.

Keep it mind, there are too many mixed genre games right now.

Honorable genres: Stealth, hack 'n Slash, Rhythm, RTS, survival horror, visual novel and interactive movie.

Last gen it was first person shooters which was a big groan.

This gen it is open world games and I couldn't be happier.

Fine, let's get more explicit: the Sandbox Action Adventure/Shooter(sometimes) genre.  Basically, the Ubisoft sandbox.  Far Cry 4, Far Cry Primal, Assassin's Creed (alll of them), Mad Max, Ghost Recon Wild Lands, the list just goes on and on and on.  And so many of these are almost the same game, just a big map with nebulous, bland content.  Which is why I consider it over saturated, it's gone past being merely prolific (which I am totally down with) to being detrimentally saturated.

Shooters are wide spread but there's considerable creativity coming back with Splatoon, Overwatch, DOOM, Wolfenstein: The New Order, etc. 

But yeah, indies are NOT a genre.  Indies can be anything.  That's the whole freaking point of being independent in the first place.

Definitely " retro inspired 2d platformer"