GungHo Online Entertainment's Puzzle & Dragons is a game that contains both puzzles and dragons. It's generated more than three million downloads in Japan. I'd say a good half of those downloaded it simply because the game's name features all anyone really needs in a video game.
Puzzle & Dragons is an amazing combination of turn-based monster collecting role-playing game and match puzzler. Players collect creatures of different elemental types, form a party, and then attempt to match gems corresponding to those elemental types in order to increase their creatures' attacks during battle. As they level, creatures earn powerful skills that can be unleashed once enough of their element is collected.
It's so much fun.
Remember the card collecting game I wrote about the other day? Ayakashi Ghost Guild? It's got the collection and fusion bits of that game, with gameplay that doesn't immediately put me to sleep.