The general gameplay is fairly standard for a game of this type: fight through numerous stages, each with their share of opponents, until finally reaching the boss Pokemon, which is sometimes Legendary, but is also sometimes just a giant version of a non-Legendary Pokemon. Other Pokemon can be acquired as the game progresses, and the player defeats more opponents. Other modes include a two-player Co-op mode, and an all-out, fight to the finish mode for up to four players. The Pokemon in the game aren't real, however, and are in fact a collection of wind-up toys that can be made to fight each other until only one remains. An interesting concept to say the least.
Finally, passwords will be available, both in-game and on the official Pokemon Scramble website, allowing players to unlock more content within the game, specifically Legendary Pokemon. Junichi Masuda claimed around two weeks ago that he wanted to add some action elements to the series - this game could very well be the result.
For an in-depth look at the game in action, check out the official website at http://www.pokemon.co.jp/special/pokemonscramble/