If you haven’t already seen Perplex City, you MUST take a look! It’s a collectible card game, based on complex puzzle-solving, but with a rich backstory. It’s definitely aimed at adults, and some of the cards are infernally difficult. I’d go so far as to say it’s like Magic: The Gathering for grownups, only much, much better!
My friend, Edmund, passed me his spares on the weekend, and I’m hooked!