There are two different versions of Aztec Challenge; the original (copyright-dated 1982) and an improved rewrite (dated 1983). According to the author the original version (green man, wavy background) was originally known as "The Bonifas" and released through APX. Cosmi tweaked it and renamed it "Aztec Challenge". The rewritten version (gradient background) is still far from the best Atari game ever, but it's not that bad, and kind of fun. The Top Ten and (AFAIK) Ariola releases both feature the rewritten version. Cosmi also released a C64 "Aztec Challenge", but that appears to be a very different game that just happens to have the same name.