- Sonic the Hedgehog 2 contains data for a cut level called “Genocide City”
- Obscure Wolfenstein clone Corridor 7 randomly jumpscares the player with a red demon face during regular gameplay
- Dog Island, a Wii game in which all the characters are adorable chibi dogs, has a subplot about a doctor whose botched treatment caused the death of someone he loved many years ago. He still sees her in his dreams, unable to let go or move on.
1987 text adventure Jack the Ripper (along with a handful of other games) was developed by an organization that might have been a neo-nazi sex cult.
Speaking of video games with in-lore cults, Kanye Quest 3030
Nah, this cult wasn’t in the game lore, this cult might have been real.