CoroCoro magazine in Japan has revealed that Pokémon Rumble U will be releasing in Spring in Japan only on the Wii U eShop.
Known in that part of the world as Pokémon Scramble U, the game continues the action spin-off series of the Pokémon franchise, and will let four players play together, like the original game, and will once again be developed by Ambrella. Up to 100 Pokémon can feature on the screen at any one time, and the game will have all 649 creatures from Generations I to V.
A scan from the magazine shows a new Eevee evolution, too, called Sylveon.
Cubed3 will update when more information on Pokémon Rumble U becomes available.