SpyParty is an independently developed game by former Spore developer Chris Hecker that puts a sniper against a spy in a game of cat and mouse during a dinner party. Hecker has said that it is loosely inspired by another independently developed game called Duelling Machine by Thatcher Ulrich. The core of SpyParty is a two player competitive mode where a sniper must hunt and prevent a spy from completing their objective during a 1960's dinner party. The game is said to be in "extremely fluid development", though it is unknown what that entails.
GDC 2010 Playable Version
The playable version at GDC 2010 contained filler art assets, but the core game mechanics have been well refined. There are two asymmetrical players in a single match, a sniper and a spy. The spy is given four objectives and a certain amount of time to complete them in during a dinner party. Meanwhile the sniper is perched outside a window and only gets to view the party in two modes: a wide angle where details are difficult to pick out, and a zoomed in view that gives plenty of detail but has an extremely limited field of view. All of this takes place during a dinner party populated by artificial intelligence characters who are moving about and conversing with one another.
One example task the spy is given is to make contact with a double agent by saying a special code-word. The sniper will know what the code-word is, but all must try to pick it out during all the audible conversation happening in the room to know who to shoot.
These game mechanics encourage the spy to attempt to behave like the artificial intelligence to not be easy to pick out of the crowd. Meanwhile the sniper must balance full party awareness with the details required to take out the spy.
As of June 6th, 2013, Spy Party has entered an open alpha state, with $15 US being the price to buy in.