King's Quest: Epilogue (aka Chapter 6 or Episode 6)
Enjoy this bonus King’s Quest Playable Epilogue! Only available through Complete Collection purchase.
According to the developres the Epilogue is more of a bonus chapter not an ending.
Behind the scenes
This is also known as Chapter 6 in some of the materials and file names, and by Sierra/Activision themselves. It's also referred to as Chapter 6 on the Playstation store website.
This may have seen been added to 'Season Pass": owners as well in some formats. It's advertised as such on the PlayStation Store. It is not available with the Steam Season Pass.