So, it's an ARG, not a video game, but I think this is the place to post about it.
www.perplexcity.com is the site. It's pretty interesting. You solve puzzles from cards you can buy and you try to solve the mystery of where this cube was hidden on Earth. In the end, the first person to find out the location of the cube wins $200,000 (in real money, not ARG money).
At any rate, if anyone else is playing, perhaps we could trade duplicate cards (with the stuff NTO scratched, of course). Let me know...