I highly recommend Bust-a-move Universe for 3DS (I personally played it on my 2DS). It's a really fun puzzle game where you shoot bubbles to match the same color and get them to disappear. An Amazon reviewer recommended Space Bust-a-move as well, but I didn't like that as much. In that one, if you got a game over on a puzzle you had to start the whole world you were on over again, which means you could have to replay puzzles you already beat. Plus Bust-a-move Universe has a guideline that is always on so you can see where your bubble will land.