Guitar Hero, a series currently on hiatus, may have had a different direction in a pitch for what could have been Guitar Hero III.
Whilst designers Steven Kimura and Joe Kowalski were working at Harmonix, the pair put together a video pitch for a concept dubbed "Rockapocalypse" - a dystopian future where rock music has been banned, guitars set on fire - for all the wrong reasons. The only songs that remain are those that people remember, setting a rather different tone to the standard "become a rock legend" proceedings.
According to Kotaku, it did gain some ground - but then the series went onto Activision subsidiary Neversoft and Vicarious Visions, with Harmonix going onto create Rock Band. The rest is rhythm history.