 Portal 2 is a first @-@ person perspective puzzle game . The Player takes the role of Chell in the single @-@ player campaign , as one of two robots — Atlas and P @-@ Body — in the cooperative campaign , or as a simplistic humanoid icon in community @-@ developed puzzles . These four characters can explore and interact with the environment . Characters can withstand limited damage but will die after sustained injury . There is no penalty for falling onto a solid surface , but falling into bottomless pits or toxic pools kills the player character immediately . When Chell dies in the single @-@ player game , the game restarts from a recent checkpoint ; in the cooperative game , the robot respawns shortly afterwards without restarting the puzzle . The goal of both campaigns is to explore the Aperture Science Laboratory — a complicated , malleable mechanized maze . While most of the game takes place in modular test chambers with clearly defined entrances and exits , other parts occur in behind @-@ the @-@ scenes areas where the objective is less clear . 
