The release of the REDkit modding tools has opened up The Witcher 3 like a Yuletide goose, resulting in finds like an extended version of the ending in which Yennefer pulls off a shocking betrayal. Less plot-relevant but still pretty neat, modder MerseyRockoff has found the audio and text files for a cut series of quests where Geralt could enter a string of boat races, and set about recreating them.
As MerseyRockoff notes, "all the conversations, characters, notices and journal entries featured...