Atari 2600[edit]
Developed by Activision and released in 1989; this rather primitive conversion only allows two players to play simultaneously.
Atari 7800[edit]
Developed by Activision and released in 1989; this conversion again only allows two players to play simultaneously.
Commodore Amiga[edit]
Developed by Monarch Development and Activision in 1989; this version, once again, only allowed two-player play.
Apple II[edit]
Developed by Monarch Development and Activision in 1988; this conversion, yet again, only allows two-player play.
Commodore 64[edit]
Developed by Monarch Development and Activision in 1987; this conversion was the first and has three-player play.
Amstrad CPC[edit]
Developed by Monarch Development and released in 1988; this version, for a fifth time, only allows two-player play.
Atari Lynx[edit]
Developed by Atari and released in 1992; this version allows four-player play, with the fourth player being a big rat.
Nintendo Entertainment System[edit]
Developed by Data East Corporation, and released in 1988; this version for a sixth time only allows two-player play, and it does not actually feature Ralph either (as evidenced by the cover art, which only features George and Lizzie).
Sega Master System[edit]
Developed by Sega and Activision, in 1988; this version, for the seventh and final time, only allows two-player play.