Portal is Valve's 2007 first-person puzzle game set in Aperture Science, where test subject Chell solves chambers with a portal gun under the supervision of the AI GLaDOS. Buttons and Weighted Storage Cubes are core mechanics, used to hold doors open and trigger platforms. GLaDOS names this floor switch in her typically verbose, deadpan style during the early chambers, teaching the mechanic while establishing her personality. The line became a quotable example of the game's writing and is shared by fans in edits, streams and soundboards long after release.