Click in the game area with your mouse or hit the 'S' key to
start. Use your mouse to sight an approaching ship in your
cross-hairs. A target box will light up when an enemy ship is in
your sights, giving the craft's closing speed and range. Click
the mouse button to fire.
Whenever an enemy fighter gets past you, it will fire on your
ship. You will see the screen flash and shake if they score a
hit. Watch your shields - when they go, so do you.
You can pause the game at any time by hitting the 'P' key. Hit
again to resume. Use the 'M' key to toggle sound on and off.