Tsum Tsum is a mobile game available for iOS and Andriod devices via their respective app stores. It started out in Japan and the game is tied to a Japanese social network called LINE.
A "Tsum" in the game is a small character icon. Tsums of different characters fall from the top of the screen and fill up the play area. As you clear them more fall from above. The goal is to clear them as quickly as you can. Each game lasts a minute (although the time can be extended based on your actions in the game).
You clear them by swiping your finger across Tsums of the same character that are next to each other to connect them. If you connect 3 more Tsums, when you lift your finger they will be cleared. The more you connect at once in a chain, the higher the score you will get.
If you connect 7 or more of the same character a "Magic Bubble" or a bigger version of the Tsum will appear. You can click the Magic Bubble and it will clear all the Tsums around it. There are several types of bubbles and they have extra abilities depending on their type.
If you get a big Tsum you can connect it with other Tsums of the same character but it counts as 5 Tsums on its own.
In addition to the characters that you clear in the game you also have your characters that you collect (more on this in the Characters section). You start out with Mickey as your only character. Each character has a special ability that charges up when you clear Tsums of your character.
As you are clearing Tsums you earn 3 different things: Coins, Points, and Experience. Coins are mainly used to buy boxes which contain additional characters. Expierance increases your level. Points are basically just your score for a game.
Of course like most mobile games Tsum Tsum has a social aspect to it; however, since it is originally Japanese it is tied into a Japenese social network named LINE. In order to save your progress, use your account on more than one device, and add friends in the game you will need to create a LINE account.
Have questions or want to discuss the game? Head over to the dedicated forum on Character Central to discuss all things Tsum Tsum.