Valve has just announced an amazing deal on Steam: you can download the original Portal game for FREE on Steam until September 20. The great news is that if you download it by then, it will be yours to hold forever and you’ll never have to pay a single cent to play the amazing game.

This is part of Learn With Portals campaign from Valve, which aims to promote Portal’s reality bending puzzles as an educational tool and, of course, hopes to turn the players into little genius-addicts that will create even more complex puzzles.

But until then, I guess that it’s a good idea to visit Steam and download Portal for free until Semptember 20th – afterwards, it will just be too late!