When he activates his special ability – telekinesis – one of his eyes turns blue and the other disappears. He has small white “apples of the eyes” when he is calm, but these dots disappear once Sans get angry.
He also has a white shirt, black pants, and slippers on his feet. The main character escapes from the Ruins, then he acts as a supportive hero for those who follow Neutral and Pacifist scenarios, and appears as the boss at the end for those who choose Genocide scenario. For the first time, players will see him at Snowdin Forest. He is the major hero of the title and a brother of Papyrus. One of them defiantly is Sans, the skeleton.
Also, memorable and interesting characters attracted numerous players – all of them have their original stories, appearance, traits, and style. Not only the game conquered the audience with its cool gameplay, visual style, and even philosophy of nonviolence. One of the best old-school style games of the last decade – mysterious Undertale – took the Internet by storm.