Hollow Knight is one of the better games I've had the pleasure of playing, and it's unquestionably the best indie game I've played. My rating is a nine out of ten, with one point deducted for some infrequent control functionality.
Have you tried Cave Story? It doesn't get any more indie than that- every single aspect of the game made by one guy. And it is also an incredibly tight and polished platformer that follows all the genre conventions, and then violates many of them intentionally and thoughtfully.
I'd give them a 9, knocking down a point for what happens after you collect all of the grubs