Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

In Portal player must solve physical puzzles and challenges by opening portals to maneuvering objects, and themselves, through space, and  rewrites the rules for how players approach and manipulate their environment.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 introduces players to a host of fresh puzzles and devious new test chambers in never-before-seen areas of Aperture Science Labs. It also reunites them with GLaDOS, the occasionally murderous computer companion from the original Portal.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Portal 2 is a stand-alone, full-price retail release with new gameplay mechanics, story line, and some surprising new twists.

Valve announced that Steam has added paysafecard to its collection of payment options for customers in many European countries. In celebration, customers who spend 20 EUR or 20 GBP on Steam using paysafecard before August 25th will receive a free copy of Portal.