Brainstorm: Voice-Based Game
Real-Time Response
Users command units using their voice. Possible applications include:
RTS (helps with micromanagement by allowing a user to command troops with your voice)
Sports (call out your plays, eg. "Defense!")
Sidekick Adventure/Platformer, eg. Jak and Daxter: Command your sidekick with your voice while you control your character with a controller.
NOTE: Tone could be given utility. If you shout "ATTACK NOW" loudly instead of whispering "please go attack" softly, you'll get a more immediate response. This could also impact the emotions of those you're commanding. If you're consistantly harsh, you could hurt the feelings of your sidekick or troops.
Zany Minigames/Puzzles (eg. Wario Ware Mega Microgames, Inc.)
Telemarketing
Preaching
Waveform Puzzles
Roleplaying
Actual voice interaction with NPCs integrates the players in the fantasy world.
Certain classes impacted by voice (eg. Bard)
Distance based chatting--if other PCs and NPCs are far away, you can either not hear them or hear them faintly.
Game Show
Host your own game show!
Like You Don't Know Jack, but one person serves as the host. Niche topics, like WWII history, would draw specific subsets of fans that would allow for expandable content.
Education
Teaching singing as a skill.
Programming for educational interactivity.
Performance Based Games (eg. Dance Dance Revolution, Karakoke Revolution, any sports game)
People usually have to sit around waiting for their turn. But what if when spectators boo or cheer, it actually impacts the game? Taking DDR as an exaple, if you get cheered you might get more points, but the arrows could come faster. This concept is adaptable to just about any game with spectators.