An interesting installation from Northern Ireland, called Block H. It features a FPS game built as a Counter-Strike mod, which uses environmental cues from Northern Ireland, including the sectarian murals that are fast disappearing from that landscape. The installation also hopes to ask questions about media, memory, and "militainment."

Here's how the game works: via local network or Internet connectivity, teams are split into Loyalists and Nationalists. Players wear Celtic and Rangers jerseys, denim jackets and anoraks. The game is set in a housing estate split by a peaceline and watchtower. Each side has its own versions of sectarian symbols: murals, bonfires, flags, drums, graffiti etc. Details were based on hundreds of reference images to create a composite environment of Belfast and Derry. The game is projected on two sides of a translucent white tent, whose insides are projected with television footage of "The Troubles."

It's always a bit hard to tell how high-concept installations like this really work without seeing them in person, but there is additional documentation on the website that makes it a bit clearer. You can also download the Counter-Strike mods and the like.