Tōzoku to 1000-biki no Pokémon is a game based on the 17th Pokémon movie Diancie and the Cocoon of Destruction. In the game, the thieves from the movie have stolen jewels that the player must steal back. The player controls a goup of Pokémon that must defeat the thieves' Pokémon. The player chooses Chespin, Fennekin, or Froakie at the start of the game to be the group's leader. During each stage, the player sends out a group of Pokémon to battle an enemy group. The A button sends out Froakie, the X button sends out Chespin, and the Y button sends out Fennekin. Defeated Pokémon cannot be replenished untl the stage is completed, so the player must carefully send out only enough Pokémon to defeat the enemy group. It is possible to sneak past enemy groups without getting caught, preserving the amount of Pokémon in the player's group.
The game is compatible with StreetPass, allowing the player to receive the Pokémon that other players set as their leader.