Released near the tail end of the Atari 2600's popularity (some might even argue that it missed the tail end), this conversion only manages to get the gist of the gameplay in tact. However, given the age of the system compared to the age of the game, some find it quite remarkable that this version even manages to accomplish what it does.
Atari 5200 & 8-bit computers
A remarkably faithful home conversion of the game, this version unfortunately uses one of the lower resolution graphics modes of Atari computer systems. Despite the lower quality of the visuals, the background music is faithfully reproduced. Aside from the controls, the Atari 5200 version is identical to the Atari computer version. An alternate version was commissioned by Parker Brothers, being developed by Anthony Weber (responsible for some other arcade accurate ports to the Atari computers), but they went with the released version at the last minute.
Of the contemporary home conversions of the arcade game, the Colecovision version is probably one of the nicest looking, as it supports one of the higher resolutions. However, the motion of the player and the enemies isn't as smooth. Contains all of the features of the game.
This version probably offers the best compromise of visual quality and gameplay accuracy of any other contemporary version.
NES/Famicom Disk System
This conversion of the game was first released in Japan on the Famicom Disk System, and later released in North America as a cartridge for the NES. More of a sequel than a conversion, this version expands upon the original, adds boss battles and more elements, and incoporates aspects of the Gradius series into the game. See the NES walkthrough for more information.
Xbox Live Arcade
Essentially a direct port of the arcade game for the Xbox 360 with an optional upscaled mode which includes enhanced visuals such as a more realistic space background at a higher resolution. Extremely accurate, and includes online cooperative play and 12 unlockable achievements.
Game Boy Advance
This extremely arcade accurate conversion is contained in the compilation title Konami Arcade Classics. Aside from the compromise in resolution due to the GBA's limited screen space, and the movement of the score to the side of the screen, this version is very faithful to the original.
Tucked away in Contra: Legacy of War as a hidden mini-game, players can access this condensed version of Gyruss either by finding a secret arcade in the second stage, or by entering the following code at the title screen: , , , , , . This version has more in common with the FDS/NES conversion of the game than it does with the original arcade version.