Melancholy of Haruhi Suzumiya dancing game works. It'll feature the Hare Hare Yukai dance, of course, but it will also feature new dances! Dancing through the main game will unlock options for the "free mode," including costumes, locations, and songs. In free mode, you can play the song of your choice. This is also where the three-player multiplayer is available. This mode is also being touted as enabling exercise, though we don't know if that means some kind of exercise/health-related (calorie count, etc.) will be included. It is also currently unknown whether the two remaining SOS Brigade members will be playable, but they're male and therefore a low priority.
The SOS Brigade icon in the corner of the screen reads "Action!" to alert players to the start of a stage. The life bar starts at full and decrements along with missed movements. Moves are to be performed while move icons are inside a generous red bar, which makes the game look fairly easy.