On December 7, 2022, the game's official Twitter account announced the release of UKButt, an official mod which adds overall controller rumble support to Ultrakill by running buttplug.io, an open-source program that allows select video games to interface with rumble motors in Bluetooth-connected devices, and is especially designed and marketed for use with adult toys. The announcement described the mod's release as the "Sex Update," referencing a longtime meme among the game's fanbase which jokingly demanded that Hakita "add sex to Ultrakill," to the point of leaving tongue-in-cheek negative reviews on Steam.