Navigate the player to the landing pad through twenty increasingly difficult levels within the time limit and with enough fuel. Movement or firing uses up fuel though levels can be replenished by shooting the fuel dumps. Running out of fuel means you loose control and can't fire. If all fuel dumps are destroyed on any given level the player's fuel tank capacity is doubled for the next level (this does not apply to starting from the highest level reached).

Avoid the moving doors and increasingly fiendish enemies, find the switches for the doors that block your way.

When a life is lost the player is temporarily shielded against enemy fire, this is represented by an electrical circular field around the lander just after it is respawned.

Don't touch anything - that would be fatal!

Be careful though, loosing a life resets the current level and loosing the last life ends the game.