Spider-Man and His Amazing Friends (1981) was produced at the same time as this show, albeit with a different voice actor as Spidey and most of the other characters. The two shows even premiered on the exact same date.
This series takes place in the Earth-8107 version of the Marvel Comics multiverse, together with Spider-Man and His Amazing Friends (1981) and The Incredible Hulk (1982).
While Amazing Friends is more widely recognized for its guest-stars, Spider-Man managed to sneak in its own cameos. This included a cartoon based on the Avengers shown on a television screen and a store called Stan's Costume Shop which featured numerous Marvel characters.
Toei acquired a license to produce Marvel-based content in Japan in the late 1970s/early 1980s resulting in TV series like Spider-Man and super sentai as well as animated films based on Dracula and Frankenstein's Monster. However, with this Spider-Man animated series, Toei began producing Marvel content for an American audience. Beginning with the concurrent series Spider-Man and his Amazing Friends, Toei largely took over animation duties on Marvel Productions.
When NBC rejected the pitch in favor of Spider-Man and His Amazing Friends (1981), the show made it to syndication by ARP Films in 1982 for a limited syndicated run. It eventually get wider distribution in 1988 by Marvel Action Universe (1988).