During Nintendo Direct today, Pokemon Shuffle was announced for the 3DS. Pokemon Shuffle is a free game that will be downloadable from the Nintendo 3DS eShop in February. It features in-app purchases, because it's kind of like a Candy Crush game mixed with Puzzles and Dragons.
You start with five hearts, and battling takes one heart away; so if you run out of hearts, you need to wait for them to replenish or you need to level up. In each battle, you have a limited number of moves to make. You make matches of three or more to deal damage to the Pokemon you are battling. You need to defeat the Pokemon within the number of moves or you have to retry the level.
Each Pokemon has a type and level, and you can battle more effectively by capturing more Pokemon and leveling up. There are also items that you'll get in-game, and that you can purchase. Also, some Pokemon have mega evolutions that do more damage.
Pokemon Shuffle is coming in February.