The mid 1980s was one of the best times in the early days of home computers. There were a relatively huge number of options available if you wanted a computer, none of which were compatible with anything else for the most part. As this ad by Activision indicates, major computers included the Commodore 64, Apple II, Atari 8-bit and Coleco ADAM. In 1985, even though Activision may not have been developing games for them, other viable computers included MS-DOS based PCs, TI-99/4A (though recently discontinued at this point), Macintosh and the newly introduced Atari ST and Amiga among others.
The ad is a little misleading though as not all of the games were available for all the systems mentioned. To be fair, the Coleco ADAM, for example, would shortly be discontinued (if it hadn’t been already when this ad appeared) but it was compatible with most ColecoVision games. It had some questionable design decisions and early high failure rates doomed its chance for success.
The games in this ad are all Activision classics. Space Shuttle was a space flight simulator that was quite detailed and complex for the time. An incredible achievement but not a game for someone looking for a quick shoot-em-up. It was available for the Atari 2600, Commodore 64, Atari 5200, and Atari 8-bit computers.
Zenji was a puzzle game in which you controlled a smiling face through a maze while avoiding obstacles. Your goal is to turn the maze green while connecting each section and avoiding obstacles. It was available for the Commodore 64, Atari 8-bit, Atari 500, and ColecoVision.
Beamrider is a shooter that could be described as a pseudo 3D version of centipede. It is relatively simplistic but well done. It was originally developed for the Intellivision then ported to the Atari 2600, Atari 5200, Atari 8-bit, ColecoVision, Commodore 64 and others.
Finally, there is H.E.R.O., my personal favorite of the bunch. H.E.R.O. stands for Helicopter Emergency Rescue Operation and in this game you use a helicopter pack and other items to rescue trapped miners. You navigate through various tunnels with your helicopter pack blasting obstacles with dynamite and zapping ill-tempered creatures such as spiders with your helmet mounted laser in your attempt to find and save trapped miners. It was available for the Atari 2600, Apple II, Atari 5200, Atari 8-bit, ColecoVision and others.
All of these games are quality games that are worth playing still today. Some or all have seen various compilation pack re-releases but if I had to pick one platform to play them all on, it would be the Commodore 64. Screenshots above are from the Commodore 64 versions.