If you look at the macro level, it sounds ridiculous to say Celeste stands out, but how many platformers with the same game feel, and similar art style polished to the same degree came out in 2017-2018? I don't personally know, but I'm assuming there wasn't any, and if there was, they were limited in number.
By game feel, I'm referring to animations (they influence how the game feels to play, they're bouncier in Celeste compared to other platformers), movement speed relative to level unit (blocks of 8 pixels, in this case), jump (height, length, cancellation, coyote time, buffer period), gravity (upswing, downswing), and a few others I'm too lazy to think of now.