As well as sitting down with Valve's Jeep Barnett, we were privileged enough to get hands-on with a PS3 build of the game out at Valve Software, where we had three sections of single-player available to play, as well as a few hours of co-operative play.

So if you want to know how Portal 2 really does stack up to the first in the way of visuals, puzzles, plot and humour (the first one was quite funny), we've put together as extensive a hands-on preview as possible based on what we played. We also have a host of new screens, some of what are exclusive to this preview of the game, and all of which you can check out by clicking the thumbnails below.

Click here for the full preview.