* When you start the game, your star ship will be in the middle of the screen. The computer voice will state 'Alert, alert, invaders sector 1, player 1, battle stations'. With that, you are ready to rock and roll. Before you start your game, be sure of what version machine you are playing so you can get yourself prepared. Since each version alters the order of the aliens, it's not good to be prepared for one attack and a totally different attack comes along.

* Although the computer voice can be annoying at times, it also gives you very valuable information. This will actually help you to concentrate more on destroying aliens then constantly looking at your gauges. Some helpful things the voice will tell you are :
1) When your fuel status hits marginal and critical.
2) When your laser temperature is approaching critical.
3) The countdown after you activate warp.

* Fuel is a very precious commodity in this game. If you run out of fuel, your game is over regardless of how many star ships you have left. Learn how to maximize your fuel usage because in the later sectors that have a lot of waves, you will be running on empty. Some other fuel facts :
1) When you activate warp, only the enemies on the screen slow down. Your fuel supply continues to burn away in REAL time.
2) When fuel status marginal is announced, you have approximately 25 seconds of fuel remaining.
3) When fuel status critical is announced, you have approximately 8 seconds of fuel remaining.
4) Shooting the fireballs in the asteroid wave will get you 3 more seconds of fuel.
5) You score double points during fuel status critical.
6) At the end of each sector, you will be re-fueled when you dock with the mothership.
7) Losing a star ship doesn't replenish your fuel supply.

* The warp button can be a blessing or a curse depending on how you use it. You only get one warp per sector or one per star ship. This works fine on the lower sectors that only have a few waves. On the higher sectors, though, you must plan (if possible) the best place to utilize it. Some tips :
1) If it is used on an enemy that goes across the screen, wait until they are halfway across before activating the warp. This way, you can get them all before your warp time runs out.
2) If used on the diagonal flying aliens, again, wait until a lot of them are out before activating.
3) For other aliens, make sure they are mostly on the screen. Sometimes, these aliens disappear off screen and if you activated your warp too early, it will be wasted while they hang around outside of the playing area.

* There are no safe places in this game so you must always be on the look out for not only the aliens dropping on you, but also their laser fire.

* Speaking of laser fire, your ship is equipped with a powerful laser cannon. There is no limit to the amount of shots you can fire, but there is a catch. The cannon heats up with each shot fired. It will overheat if you fire too many shots too quickly, and you will have to wait about eight seconds for it to cool off before you can fire it again. Some ways to prevent overheating :
1) Make your shots count. Don't hold down the fire button to take out the aliens. Shoot to kill, not to warn.
2) If you must do multiple shots, do it in short bursts. Your laser heats up much faster then it cools down.
3) If you do overheat, just avoid the aliens and their fire until your laser is operational again.

* Docking is the easiest way to get a lot of points. You need to set yourself up after the last of the asteroids in order to get those points. Moving your ship during docking procedures will prevent you from getting any docking bonus. The most points are from the 'Paint Scraper' method : Line up your left engine over the C in SECTOR. It will look like you will collide with the left docking arm but you will barely squeeze by. Thus, you now have 1,500 points.

* Also, if you destroy your star ship during docking, your game will be over regardless of the number of men you have left.

* Always expect the unexpected in this game. Sometimes the aliens will do things or make moves you haven't seen before. The best way to counter this is to always be on guard.

* After sector seven, the sectors repeat again. Also, the score 'rolls over' at 99,990. Many players will intentionally get themselves killed when they get close to this score in order to claim the number one position on the board.