Recs.
Updated
Street Wars, unlike most games, immerses itself as part of your life. The game takes place across the landscape of your city, with you being assigned other players (typically complete strangers) as assassination targets, on whom you're given a few facts. Your task is to then monitor these individual's daily lives whilst still going about your own (and watching out for anyone who might be after you) and to "assassinate them" by squirting them with a water pistol. You then take on that person's target as your own. After completing all of your kills you're then on to defeat the boss; the master commander.
Specs
Pros
Pro Unusual Concept
A game that takes place within your daily life is different to so many others. With most games you can choose when to start and finish, or they're at least time bound by a few hours. This game goes on for weeks, following you wherever you may go, and requiring you to use wit and cunning to manipulate others (both players and bystanders) appropriately to allow you to complete your tasks.