Cuphead is one of those games you will never see done again, it truly has its own unique identity. The game was a test of skill and patience, but throughout it all there would always be the constant thought of "ok just one more time" right when the game reveals to you how far you got on a boss. I don't think I've ever played a game where I just wanted to keep playing until I mastered it. The 200% completion is a huge hurdle to jump over, but once you do you'll feel like you really mastered the game.