Quickie: For those who bought and played Portal, from Valve Software (PC).

If you liked the game, I bet you even played the Flash version.

So, t he same guys who made Portal Flash, advanced a stage and created a map pack for Portal 3D based on Portal Flash.

Click to get it:

All for FREE! According to them, it adds 3 and a half hours to the game… so, almost more than the game itself! O_O

Have fun!

- source from Kotaku. Thanks guys!