Je can control with your cursor the laserbeam of you by clicking somewhere on the screen. Take care you destroy the enemy before it destroys you.(If you click somehwere on the screen you get an explosion. If something of the enemy touch it, that will be destroyed)
By clicking on start, the games begins. Je can take a break by clicking on "suspend" (the middel button).
You must try to protect as long as possible the 5 cities against enemy attacks.