Quickstart instructions:
* Type 'start' to begin the game, then use the mouse to
control your player (left mouse button forwards, middle
button backwards and right button to fire).  The cursor keys can
also be used to control your player (and 'a' and 'z' to move forwards
and backwards, and SHIFT to fire).
* The winner is the last person left alive when the game is over.
* Pressing ESCAPE in a game will quit the game and pressing
the space bar will get the mouse pointer back to normal.
* Grenades can be launched by pressing RETURN when another
player is in line-of-sight.
* Rockets can be fired by pressing 'r' when another player is in
line-of-sight.
* Mines can be dropped by pressing 'm'.
* Collide with the red diamond objects to collect extra energy.
* Collide with the cube objects to collect extra weapons.
* Below a minimum distance guns have no effect and grenades and rockets
can't be launched (when the targeting sight is black instead of red).
* The game window can be resized (the game will then run faster or
slower).
* Pressing 'f' during a game will display the frame rate.
* Point to a player and press 'i' to find out their name.
* Press 'w' during a game to find out who else is in the game.
* Collide with the black portal objects to teleport between rooms.
