That's what you need as an indie developer. A lot of publicity and great art. It doesn't matter that you essentially reproduce the exact same recipe as any other Nintendo platformer, as long as you have great art and music, people will love your content.
Similar to hollywood movies being a rehash of each other with different actors and a different setting. It's all about the human condition.
So yeah, in the rare case of Cuphead, they will do well. Maybe enough to make the next one, if they didn't over-extend themselves.
For most small indies though, I can tell you first hand, it's tough. Especially since the whole Hello Games and No Man Sky's debacle, every 'gamer' out there is out to hate indie by default. We're scammers in sheep clothing.