This game is among
the best ways to blow 15 bucks. This
game can be played anywhere with enough flat space to lay out the
cards and with any number of
participants - even
alone.
Since the rules are so simple, the game crosses cultural and linguistic barriers; I played Set many a time in Japan with host families and students at my school. I can't explain the simple rule "If two are, and one isn't, then it's not a set" in Japanese, but I had the kids playing Set like a pro within 10 minutes.
It's not a CCG. Set can be played equally by 7-year-olds and 50-year-olds. Age is no advantage. Experience is only a minor advantage; I usually win the first two or three games, after that, things start evening out.
Set would make a lousy computer game; the computer could identify every set in a layout within microseconds. It would make a good (and simple!) network game, though, and probably could be implemented easily in Java by someone who knew what they were doing.