I was wondering if they actually existed. Plenty of Internet sources reference them, but there isn't a lot of primary/secondary sources.
Judging from magazine articles and early Artic adverts, they did actually exist, though.
See...
Your Computer August 1981 article, announcing the release of (what would be) Adventure A for the ZX80, with a ZX81 version to follow soon...
Early Artic advert, which lists the first three Adventure titles as being available for the ZX81/80... (from 1982)
And, not really connected, here is one of the earliest Artic adverts I could find, listing their titles for ZX80. I think we probably need to add some of these to ZXDB too... May/June 1981
