Galaga '88/Versions

Sharp X68000
Developed by Dempa Micom-Soft and published by Namco for Japan in 1988. As with the majority of ports to the X68000, this version is extremely similar to the original arcade version. However, it does contain a number of arranged bonus stages which draw upon other characters from older Namco titles, such as Pac-Man, Rally-X, Dig Dug, Mappy, and Xevious, as well as previous titles in the Galaxian/Galaga series. These arranged bonus stages were complimented by background music remixed from their respective games.

NEC PC-Engine/TurboGrafx-16
Developed and published directly by Namco for Japan in 1988, then the United States in 1989 as Galaga '90. Contains a simplified set of enemies, although it does introduce a fourth exclusive escort enemy which resembles a medium sized Galaxian. A Difficult mode can be accessed by holding while pressing. In this mode, several new capsules can be obtained by successfully destroying the last enemy in particular stages while they are flying through the screen.

Sega Game Gear
Developed and published directly by Namco for Japan in 1990, under the name of Galaga '91. Unlike the X68000, its year does not match to its title.