A critique of Galaga

Galaga is a top-down shooter game released in 1981 originally for the arcade and continues to have a following today (27 years later, at the time I’m writing this article). This game is a derivative of Galaxian, and to a less direct extent Space Invaders.

This game’s control scheme is extremely straightforward – there is a joystick and one button. It is also noteworthy that the player can only maneuver the avatar left and right, there is no vertical control. A player can understand all major control mechanisms the first time they play the game.

Galaga follows very consistent structures throughout the entire game. The player usually comes to expect certain patterns and the game which can give a feeling that the game is “fair”.

There are only 4 enemies in the entire game (I believe), and their behavior doesn’t change dramatically throughout the game. Blue and Red bad guys explode after one hit. The Boss enemies (Green and yellow) die after two hits, but change color after one to give the player feedback on their status.

There is only one ‘power up’ in Galaga, which is probably the most famous feature of the game. The boss enemies can capture the player’s ship, which the player can win back by careful play – giving the player control on a double ship.

The implementation of this design feature is unique in that when a player gets this ‘power up’, it is as much a liability as it is an asset. The avatar shoots two shots at one time, but also is twice as large – making it an easier target. There is also the possibility that the player will accidentally shoot his own ship, loosing a life in the process.

The levels follow a recognizable pattern: The enemies fly onto screen in a predetermined formation, sometimes firing or attacking. Then they fall into a pattern at the top of the screen. Lastly they take turns coming down to attack individually or in small groups until all enemies have been vanquished.

Each leveI becomes slightly more difficult with the exception of the bonus levels. I believe that every 4th level is a “challenging stage” which is a bonus level where the avatar is not attacked – dropping the intensity for a while.

Feedback in this game is extremely fast and clear to the player. There are audio cues for firing a shot, for hitting a target, as well as the beginning of a level. All enemies are seen on screen at one time, so there is continuous visual status on progress within the level.

It is interesting that the game has had such longevity despite (or because of) its ultra simplistic user input and general predictability.