Portal is an adaptation of the 2010 Valve puzzle-platform game of the same name. It was changed from first-person into a fixed-screen side view, but the main concept is identical. It consists of twenty chambers in the Aperture Science Enrichment Center the character Chell needs to complete by using blue and orange portals to solve puzzles. She is controlled through the keyboard while a mouse or a joystick is used to aim the portals and launch them. Portals allow her to get past hazards or to trick turrets. Next to launching portals and movement Chell is able to jump, and carry and drop objects such as the companion cube. Between chambers the A.I. construct called GlaDOS often appears.
