The game can become really repetitive.
Galaga was originally released in 1981 by Namco as a sequel to Galaxian. Since then it has featured on various consoles, and has now found it's way onto the Xbox Live Arcade.
The object of Galaga is simple, you are a space fighter flying through space and you must make your way through each level by destroying waves of alien spaceships that come at you. You will begin each new game with three lives. The controls are simple, you can only move left or right and there are two buttons which you can use to fire, although both buttons produce the same effect.
There are three types of enemy alien ships on this game, and they make their way onto the screen in waves, commencing fire as they appear on the screen. Once all the waves are on the screen, the alien ships will kamikaze dive at you, whilst also shooting at you. The three enemies are as follows, Blue Aliens, Red Aliens and Boss Ships. Each are worth a different number of points, you will receive less points for destroying them when they are idle and more points for destroying them when they are on the attack. The Red and Blue aliens will kamikaze dive at you and shoot you, whilst the boss ships will also do the same, as well as trying to use a tractor beam to take away your ship. If a boss ship takes your ship and you have no additional ships, it is game-over, but if you have at least one spare ship, it is possible to retrieve your stolen ship by destroying the boss ship that took it, however, you must be careful not to destroy the stolen ship in the process.
After every few levels, you will reach a bonus stage where you can earn additional points. On these bonus stages, enemies willy fly about the screen in patterns, they cannot harm you, and your objective is to destroy as many as possible before they fly off the screen. Destroying every ship in this bonus mode will earn you an additional 10,000 points.
Each level is pretty much the same, which makes the game repetitive, the only difference you will notice is the difficulty, the speed and rate of fire by the enemy increases as you progress.
The achievements breathe some additional life into this game, and there are 12 to go for, making a total of 200 gamerpoints available. The achievements include reaching upto certain stages, destroying special enemies, forming a dual-fighter and getting a perfect score on a bonus stage.
Overall, I would say this is a game that people will either love or hate. There's enough features to keep you occupied for a few days or a few months depending on how much you like this game.
If you've played this game before and liked it, then you should definitely spend 400 Microsoft Points to play it, and if you haven't played it before, then download the trial version first.