I agree with you, crayon art style mixed with the imperfections caused by cell animation sounds very fitting.
By feedback I mean, anything that makes player's input, more impactful. For example in Buckshot Roulette, If you successfully shoot the Dealer, he gets thrown out of the camera view for a few seconds. Or when you fire a blank at him, you hear the trigger going off but nothing happening to the Dealer. These are both feedbacks that the game sends to players, one is for when you do something correct, and the other one for when you make a mistake.