So, for those of you who have either been living under a rock, or just afraid of trans-dimensional travel (or cake) your list of excuses for not checking out Valve’s Portal just got shorter.

Valve is offering an extremely generous demo of Portal, which includes the first 11 levels. For you number crunchers, there are 19 levels in the game, so technically, that’s more than half of the game.

So, go get steam if you haven’t already an get your puzzle on!