Perplex City – An alternate reality puzzle game

I’ve been reading up about the puzzle game called Perplex City, which was blogged about on boingboing (here and here) and Shiny Shiny.
At its heart, the game involves solving puzzles but, in execution, it draws from the following genres:

Collectible card games – of which Magic is the best example. To play Perplex City, you buy packs of 6 cards that have puzzles on them. Each card has an individual puzzle and the cards can be combined to form other puzzles. Some of the cards are harder to find than others and, presumably, you will have to collect all of the cards to win.
Alternate reality games – like the ones used in the marketing for the movie A.I. or the game Halo 2. These games involve clues that are hidden in the real world. Characters that you can contact and that will contact you back. And fictitious web sites that look like they’re set up by real people.
A treasure hunt – with an object hidden in the real world that you have to find.

The winner gets $200,000, which will certainly be incentive for many to play. Of course, you’re likely to sink a lot of time and money into the game in order to even have a shot at winning.