And yet Shovel Knight is doing so so great. Cuphead too. Turns out retro platformers can do great. But way too many indie retro platformers are just trash with nothing to save them.

I don't think you can gauge success by looking at existing titles. It's like asking if there's a market for scifi novels. What do you find? People like scifi novels, and there are lots of scifi novels that suck and nobody reads them. Do people like metal music? There's tons of successful metal bands, and there's an ocean of trash.

Every work is unique.