In a powerful meta-commentary on the game's mechanics, Sans physically shatters the four menu buttons (FIGHT, ACT, ITEM, MERCY) in sync with the music, removing the player's agency and forcing a pure survival encounter. 3. Mechanical Complexity and Gameplay

The story of Last Breath takes place after thirty consecutive Genocide runs by the player. In the 31st run, Frisk discovers a mysterious door in Waterfall, leading to an encounter with , the "strange figure". Gaster informs Sans of the human's repetitive massacres, granting him the memories of previous resets and agitating him into a state of relentless vengeance.

His facial expression morphs to mimic Gaster’s, featuring a wide, "creepy" smile that occasionally switches to a toothless, open-mouthed grin.