Here is an overview of the game, via its teaser website:
Many characters from the Kingdom Hearts series appear as playable characters!
Depending on the stage, Disney characters will appear as guests and lend you their strength. The game features a massive catalog of over 140 songs, including music from the Kingdom Hearts series, Disney, and more. Enjoy rhythm-based action through unforgettable music.
There are four play modes including online battles.
Watch the announcement trailer below. View the first screenshots at the gallery.