Invader's Revenge

* When you start the game, your fighter will be in the middle, at the bottom of the screen above the fuel storage area with 26 units of fuel. Your goal is to blast the invaders into dust. Each wave of invaders consists of six alien ships. You will go through seven waves of invaders before you have a chance to dock. The order of the invaders is (by their point value) : 10, 20, 30, 50, 20, 30, and 50.

* The alien invaders will attempt to make you lose your fuel one of two ways :
a) By getting to the bottom of the screen and actually picking up the fuel to bring back to the UFO. You can shoot these aliens down to recover a fuel unit.
b) The aliens will drop bombs upon your fuel supply to cause you to lose a unit. These bombs can be shot down.

* Just like the original game, when the invaders get to the left or right side of the screen, they will drop down a level. In addition to dropping down, an invader may peel away from the formation and head down to attempt to take one of your fuel units.

* Learn the different formations the invaders show. Some of the formations are :
a) In a straight line across.
b) In two straight lines across.
c) In a staggered formation that resembles a '>' or '<'.
d) One invader on each row for six rows.

* When shot, some invaders don't explode. Instead, you literally will shoot them down. After they are shot, the invader will head straight toward your fighter. Make sure you quickly move from under an invader after you have shot it to prevent this from happening.

* As in "Space Invaders", shoot the right or leftmost invader to prevent them from dropping another level down. In addition, the fewer invaders there are, the faster they travel across the screen. Make sure you adjust for this.

* Your primary objective is to prevent the invaders from stealing or destroying your fuel supply. If you lose all of your fuel, your game will be over regardless of the number of fighters you have left.

* Docking can be quite a chore. You must navigate around some space debris in order to get to your base to refuel. Watch your fuel supply because you can burn it up very quickly if you're not careful.

* As the game progresses, the invaders get more aggressive and will send down two or even three of their numbers to attempt to steal your fuel. In addition, the UFO at the top of the screen moves back and forth to drop bombs on you.

* Learn to conserve your firepower and only shoot at sure targets. The reason is the fact you can only have one shot on the screen at any time.

* Since there is no cover, make sure you are moving around constantly. If you don't move your fighter around, you are just inviting trouble to happen.