Experiment 427 is a free modification for The Stanley Parable. During development, the modification got abandoned and never got finished. There is a beta version, however.
During development, the mod would begin if the player activated the Confusion Ending and clicked on the schedule. The player would be teleported out of the map and begin a new adventure. The mod also customizes the game textures. The mod would also add new objects, change the main plot, and add new rooms.
- There is a trailer for this mod here: Experiment 427 Trailer