A real-world/virtual space cross-over online multiplayer combat simulation.
(refer to jpegs in storage for explicit diagrams, and design ideas)
While in enhanced space, going about humdrum everyday activities, getting to work, if your body is still required for it at that time, buying bread, etc. You have the ability to turn on "game mode." By this time our ability to shift rapid focus between reality and enhanced reality will have improved with practise. When game mode is enabled, the user, you, me and her, and that guy across the street will fight virtual enemies interacting with the real environment.
Controls must be setup to require only a minimal amount of input to provide maximum effecacy without disturbing the evironment (street, train, car) however the processor will return a great deal of real-time effects for the input. Perhaps a glovelike device taking inputs from the thumb and two strong fingers, and the headset detecting minute movements of the eyes and neck.
Enemies would vary according to the propoganda at the time, but may include politicians, lawyers, police, zombies, nazis etc.
The game would advance in levels with the same enemies increasing in accuracy and "damage" for more experienced players. However, the enemies and other contructs of the game would be simulatneously broadcast and synced through the MAN (metro area network).
The real city, with the most virtual kills would be host to a championship party where the best players would gather in a city wide contest. Prizes would vary from year to year. Smaller prizes would include better weaponry for the game, better armour, and top winners could win the latest version of the "console" or EnR headset. Since a great deal of the calculating would be done at the central server instead of the local machines, hackers/cheaters/modders would be detected quickly.