Watch this. It's a teaser for Trainfinity, a game developed in 48 hours during the Nordic Game Jam last week. A local cooperative multiplayer game, tracks run in three lanes from one player's tablet to the next while trains begin to run on the tracks in both directions at increasing frequency. Players have to communicate with each other to prevent collisions and derailments along the line.
The design is simple enough that anybody who can operate a tablet should understand it, a major plus for a party game. Hell, you could probably sell this as a team-building exercise in how it rewards effective communication with your neighbors. I'm a big fan of this idea and hope it sees further development.