Portal 2 draws from the award-winning formula of innovative gameplay, story, and music that earned the original Portal over 70 industry accolades and created a cult following. The single-player portion of Portal 2 introduces a cast of dynamic new characters, a host of fresh puzzle elements, and a much larger set of devious test chambers. Players will explore never-before-seen areas of the Aperture Science Labs and be reunited with GLaDOS, the occasionally murderous computer companion who guided them through the original game. The games two-player cooperative mode features its own entirely separate campaign with a unique story, test chambers, and two new player characters. This new mode forces players to reconsider everything they thought they knew about portals. Success will require them to not just act cooperatively, but  to think cooperatively.

CPU:     3.0 GHz P4, Dual Core 2.0 (or higher) or AMD64X2 (or higher)
RAM:     1GB XP / 2GB Vista
VGA:     Video card must be 128 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 2.0b (ATI Radeon X800 or higher / NVIDIA GeForce 7600 or higher / Intel HD Graphics 2000 or higher).
DX:     DirectX 9.0c compatible
OS:     Windows 7 / Vista / XP
HDD:     At least 7.6 GB of Space
Note:     Mac System Requirements o OS: MAC OS X 10.6.6 or higher o Processor: Intel Core Duo Processor (2GHz or better) o Memory: 2GB o Hard Disk Space: At least 7.6 GB of Space o Video: ATI Radeon 2400 or higher / NVIDIA 8600M or higher