Valve confirms 'Portal 2' for summer

Valve has officially confirmed that it is planning to release Portal 2 later this year.

The sequel follows the 2007 original, which came as part of Valve's Orange Box bundle.

Despite not releasing many details, the video game developers did announce that the first-person puzzle title will be released in the summer.

The original saw players attempt to make their way through a series of rooms using a device that creates portals.

The game had been rumoured for some time after Valve began casting for the character of Cave Johnson.