In Slayers X, the Boise Potato Festival contains a crevasse leading to a bottomless pit. If the player manages to land on an outcropping just below the kill plane, they can access a hidden tunnel littered with messages by Adam Chase, a character in the Hypnospace Outlaw universe who assisted Zane Lofton with developing the game. According to Chase, he helped make the game as part of a promise he made with Lofton back in high school and that even though he now despises Lofton, he pities his situation as "a deadbeat dollar store manager" who believes that the game will help him and his son escape their current lot in life. The end of the hallway contains a photo of Lofton in his underwear peppered with "BWL" (short for "bursting with laughter"), the Hypnospace Outlaw equivalent of "LOL."

Two of the in-game magazines reference the livestreaming group Vinesauce, who previously conducted playthroughs of Hypnospace Outlaw on-stream. The first cover, Metal Masters, depicts both Vinesauce members Vinny and Joel, using pictures from their respective bands Red Vox and Scythelord; Joel's bandmate Frank also appears on the magazine cover. The second cover, NerdMaster, depicts Fren, a crude MS Paint self-portrait that Joel created to mimic the art style of QT, a lighthearted parody of PT. Both Vinny and Joel expressed flattery with the former Easter egg when they discovered it on-stream.