"Portal" is a first-person shooter game, which means that it is played from the view of the player character, Chell. When players get the fully-powered portal gun, they can make two portals that are linked together on some white surfaces. Chell starts out with nothing, only able to do what GLaDOS lets her, such as entering portals created by GLaDOS and using cubes that GLaDOS gives her. Once Chell gets a half-powered portal gun, she can fire a blue portal that connects to orange portals that GLaDOS puts in the rooms. When Chell gets the fully-powered portal gun, she can put both portals anywhere. 