Diablo maker Blizzard once planned a version of the series for Game Boy Color.
Named Diablo Junior, multiple editions of the game were planned so players could meet up and swap items, similar to the trading mechanics of the Pokémon series.
"Diablo Junior was intended as a single-player-only prequel to the original game," Blizzard biographer David Craddock told Shack News.
"Taking a page from Pokémon's book, the team wanted to release three cartridges, each packing a different hero in the warrior-rogue-sorcerer vein as well as items that players would have to trade for in order to collect."
Development was limited to a handful of staff, who began work on Diablo Junior after the release of Diablo 2. Versions could have hit the Game Boy Color or Game Boy Advance - or both.
"Heroes started in a unique town before heading into dungeons and wilderness zones," Craddock continued. "Diablo Junior was ultimately put out to pasture (absent of cow levels, I'm sure) because of the steep production costs associated with developing handheld games."
Craddock is currently researching Stay Awhile and Listen, an unauthorised history of Blizzard based on the testimony of more than 80 ex-employees.
Other tidbits from the era include information on another Diablo 2 expansion which never saw the light of day. The unnamed follow-up to Lord of Destruction would have added guildhalls for multiplayer clan meetings. Two other character classes were also proposed.