Galaga '88 (ギャラガ'88, Gyaraga Eiti Eito) is a 1987 fixed shooter arcade game by Namco. It is the third sequel of Galaxian (following Galaga and Gaplus). It features significantly improved graphics over the previous games in the series, including detailed backgrounds, larger enemies and more ship details. Although it was well received, fewer units of this game were produced than of Galaga and Gaplus. Galaga '88 runs on Namco System 1 hardware.

The backgrounds for Stages 15–17 (World 4) consist of the green hexagonal space stations first seen in the 1981 Namco game Bosconian. Additionally, mines similar to those used in Bosconian are used as obliterable "bunkers" in these stages.

The game Ridge Racer Revolution features Challenging Stage #2 (Dimension 1) during its loading sequence. Shooting all 40 enemies before they fly away unlocks all of the opponent cars.

The gameplay in Galaga '88 is built upon the same premise as that of the original Galaga, but is in many ways more complex and more difficult. The game is divided into a series of 29 Stages distributed through eight Worlds. The starship Galaga accelerates between Stages and Worlds and even to higher dimensions (see Dimensional Travel below).

With the exception of the third and eighth, each World culminates in a Challenging Stage. There are six such Stages to engage in any full game, and each begins with the on-screen announcement "That's Galactic Dancin'!" and has its own music to which the enemy formations dance. In any given Challenging Stage, both the design of the enemies and their formations vary according to the player's current Dimension. As in Galaga, the objective is to destroy all forty enemies before they exit the screen. However, refraining completely from touching any controls for the duration of a Challenging Stage awards a "secret bonus" ranging in value from 10,000 to 25,000 points and equal to the "special bonus" which would have been awarded for destroying all forty enemy ships instead.

Galaga '88 introduces a variety of new enemies and behaviors. Most special enemies score varying amounts of bonus points when destroyed. Some enemies can combine into larger enemies that take multiple hits to destroy, while others arrive in eggs, explode in a shower of fireworks, grow with multiple hits, or sport armor that makes them invincible while in formation. Certain enemies drop small formations of tiny creatures that wiggle their way down the screen, and still others act as escorts to incoming groups of enemies and then quickly dive at the player before leaving the playfield. Most stages also include various obstacles that appear once the enemy formation has been assembled.

At the start of the game, the player can select how many Galaga starships to start with (one or two), affecting the number of remaining lives. The game ends after the final boss is defeated, or when the last player ship is destroyed or captured — in the latter case, the player can continue the game for an additional credit. The Game Over screen shows the player's hit-miss ratio and a visual representation of their progress. If the player reaches Stage 27, the game also shows a picture of the final boss (damaged if defeated, silhouetted if not).

Captured starships

As in the original Galaga, "Boss Galagas" occasionally stop mid-dive and attempt to capture the player's ship with a tractor beam. If captured, the boss returns with Galaga in tow to the enemy formation and attacks the player. As before, it is possible to free the ship by destroying the "Boss Galaga" that captured it while it's diving. Freeing a player ship causes it to join with the current Galaga, doubling the ship's firepower.

A new feature in this game, however, allows the classic "double ship" itself to be captured, requiring a third player ship to free it, whereupon all three ships combine into a large "Triple Ship", which appears as a large single ship, has synergistically increased firepower, and cannot be subsequently captured.

In later stages, the final enemy on any screen, if destroyed, may drop one purple canister (sometimes called a "quid"), which when collected immediately upgrades a single or double ship directly to a Triple Ship, with no effect on the number of reserve ships.

Dimensional travel

Galaga '88 introduces a new gameplay element: the ability to accelerate into higher Dimensions. There are five Dimensions in the game, and accelerating to a higher Dimension yields a substantial bonus and a higher level of difficulty. Once the player's ship has reached a higher Dimension, it remains there for the rest of the game. Also important to note is that Dimension One ceases after Stage 10, so that a ship not already advanced into Dimension Two or higher will thereupon be automatically advanced, with no visual fanfare or bonus award.

Each Dimension has its own design of enemy ships, formations used in Challenging Stages, "super-boss" for Final Stage 29, and Ending Message which rolls when the player defeats that Dimension's final super-boss.

To perform an inter-Dimensional acceleration, the player must have obtained two blue cylindrical canisters (often called "tuppets") before the next Challenging Stage. The player's ship collects these canisters during play by either (1) shooting away one of the several on-screen hovering "bunkers" or (2) destroying a single large enemy (formed from the fusion of two smaller enemies together) and then catching the canister as it freefalls from the obliterated object. When caught, a canister also gives the player's ship temporary invincibility. Only one canister may drop and be collected at a time, and no more than one canister per screen may be collected by a given method, so to collect both needed canisters in a single Stage, each method of collection must be used at least once. The canisters stop appearing once the player has collected the two required.

At the end of the next Challenging Stage, any collected canisters rise to the center of the screen and detonate. If only one canister has been collected it detonates without incident, no bonus is awarded, and gameplay continues in the same Dimension. However, if the player has successfully collected both required canisters, the detonation causes a "rift" in the space-time fabric through which the ship accelerates to the next Dimension. If the player is already in Dimension Five, the normal detonation and acceleration fanfare is still shown, but no bonus is awarded.