So (!) if I remember right, the idea was to make a mobile app where:
- foursquare users are 'fodder'
- you rack up kill points by massacring venues with foursquare users in them
- kill points unlock better weaponry
- massacring the mayor gets more kill points (perhaps you become the 'slayer')
- massacring other massacrers earns you their points (bit like playing conkers)
I've taken the all important step of registering http://massacr.com. That's the bulk of the work done but I guess we'd also need: