Diablo Junior

"Wouldn’t it be cool to make like a ‘Diablo Jr.’ type thing? Pokemon' was really big at the time. We could do something similar where you could fight these monsters and get this whole different genre, age group, because ‘Diablo’ was for adults. That was the genesis of it."

- Jonathan Morin

Diablo Junior was an intended prequel to Diablo, (or port of Diablo II, depending on source) to be created by Blizzard North.

History
The idea for the game came from Jonathan Morin in the aftermath of Diablo II. While hunting for a new project to keep himself busy after the release of Diablo II, he toyed with the idea of porting Diablo I to pocket PCs. In this period, he saw a Game Boy development kit, getting the idea to make a "Diablo Jr." game. Pokémon was big at the time, and Morin had the idea of transferring the format to Diablo, where players would fight monsters in a similar manner. The game would be targeted at a younger audience than the PC games. At the time, there was a split within Blizzard North between those who never wanted to work on Diablo again, and those who wanted to continue working within the IP.

Work in the game began in 2002/'03, and lasted four to six months. Morin was given a team of 3-4 people to work on the project. Development was carried out on the original Game Boy rather than the Color version, as they wanted to get the game working on the "base system" first. Various ideas were tossed around. One point of discussion was whether to make the game a turn-based RPG, or keep it in the hack-and-slash style of the PC games. A demo was created where a top-down perspective was used. It was planned to distribute the game either on the Game Boy Color or the Game Boy Advance, and have a cartridge system similar to the Pokémon games, where different versions of the game would be released, with each version having a different character class and support for cross-system item trading. Heroes started in a unique town before moving into dungeons and wilderness areas. Morin has commented that one version would have the player play as a knight, and on the other, a mage.

After the resignation of David Brevik, Max Schaefer, and Erich Schaefer, Blizzard South had a look at Blizzard North's projects. Blizzard South hadn't been informed of the development of the game, and ultimately scrapped it due to production costs. In a 2019 interview, Matthew Householder suggested that Diablo Junior had been cancelled due to its lack of an Internet connection, whereas the previous Diablo games had succeeded because of battle.net. In the same interview, Morin suggested that the game didn't match Blizzard South's focus on "hyper-profitability," of producing a handful of games to gain long-term profits. Diablo Junior wouldn't fit this paradigm given the production costs of cartridges, and that Blizzard would have to work through Nintendo in releasing the game. Furthermore, a Game Boy game wouldn't have fitted Blizzard's PC focus.