A leaked ToysRus leaflet has annonced that Pokémon Rumble will be available via the WiiShop starting November 16th 2009. Melee! Pokémon Scramble (乱戦！ポケモンスクランブル) the Japanese version of the game was released on June 16, 2009 for 1,500 Wii Points. A website is also on the leaflet: http://www.pokemonrumble.com but is not activated yet.

The game allows battling dozens of Pokémon simultaneously in real time, unlike most Pokémon games that are turn based. Players go through levels battling Pokémon using up to two separate attacks and randomly capture new Pokémon and earn currency which can be used to buy new Pokémon or moves. At the end of each level, is a wound-up boss that must be defeated before the level is cleared. Once you have strong enough Pokémon, they can be entered in the Battle Royal which is a free for all battle against dozens of other Pokémon.

Source: PokemonSecure