I dunno if you're into PC gaming or have a PC powerful enough to run it, but Valve, makers of Half Life and other niceties, have made one of their biggest hits of recent years free for a few days.
The game in question is Portal, a first person shooter/PUZZLE.
I know several of you don't feel interest towards First Person Shooters, but just check Portal. It's free and believe me, it IS a puzzle game. No, it's not about pieces falling from above, jewels making columns or anything remotely similar.
They give you a gun that instead of blowing stuff to pieces opens two types of portals. Then you use your intelligence to proceed. It's all about pattern analysis, observation of your surroundings and patience. In short, about using that thing inside our skulls.
I highly recommend it. It's damn free too!!!
			




 With no graphics card and stuff I'm limited in what I can play.   Heck, I had to install OpenGL myself!
  With no graphics card and stuff I'm limited in what I can play.   Heck, I had to install OpenGL myself!  
 Goes to show the amount that can be done with a 17 year old FPS.
 Goes to show the amount that can be done with a 17 year old FPS.












