Just as an idea.
Multiple computers with multiple copies of the game. And they all work as if they were multiple keyboards on a single game.
Other keyboard: exactly like keyboard, except it uses a different keyboard on another computer (computer decides who gets said keyboard) can be set to a number. (Player 2 only can trigger other keyboards that are set to 2)
Other mouse: same as other keyboard, but uses mouse instead
LAN: start, LAN: stop and LAN: connect
Starts/stops/connects to a temporary LAN server.
Being that the browser relies on the flowlab server and the desktop being independent from wireless connection, it would be a desktop ONLY feature