The Band of Thieves and 1000 Pokémon is an upcoming downloadable Nintendo 3DS game developed by Marvelous. The game is available free for a limited in promotion of the 17th Pokémon movie, Diancie and the Cocoon of Destruction. The gameplay of the game is quite similar to that of the StreetPass Mii Plaza game Warrior's Way.
The core aspect of the game is building up an army of pokémon. The player's army is built up of Chespin, Fennekin and Froakie and they can collect up to 1,000 of each at one time. To build them up, the player need to StreetPass with other players of the game. Alternatively, players can use Play Coins to add Pokémon to their army.
The other aspect of the game is the battles. Battles start once the player enters a stage. It is determined by two factors. First is numbers. If the player has a sufficiently large army, then they'll be able to get through the stages and defeat the opposing Pokémon. The second factor is type. Like all Pokémon games, type is a significant factor, so if the player sends waves of the grass typed Chespin against a fire type Pokémon like Delphox, they'll require more Chespin to get through as their attacks wouldn't be very effective. Alternatively, if they use waves of the water typed Froakie, it'll take far less as their attacks would be super effective. The player selects which Pokémon by using the touch screen or the A, Y, and X buttons.
Players can see their progress on the bottom of the top screen. Their progress is the orange part that comes from the left and the opponent's is the red that comes from the right. When either color fills the entire bar, the battle is complete. Once its complete, it tells the player what and how many Pokemon you lost.
The game is based around the characters in Diancie and the Cocoon of Destruction, mainly the characters Marilyn and Riot. As the player progresses through the game, they will get tidbits of information about the movie (which can also be streetpassed). Also for completing the game, they receive a special Pikachu for Pokémon X and Y.