"Reallyjoel's Dad" is a name for a secret difficulty present in Ludosity games, introduced in an update to Iji, that makes games absurdly hard and sometimes even unbeatable. This originates from an in-joke based on a comment made by Ludosity developer reallyjoel on a YouTube video of Iji's final boss being beaten on the previously maximum "Ultimortal" difficulty, uploaded by Daniel Remar, another developer on Iji, saying "Bah, you're a noob. My dad can beat this on a much harder setting, no sweat."