Episodes 3 - 5 are all included in the final game release which also contains remastered episodes 1 - 2. You can follow its development on my youtube channel. https://www.youtube.com/user/VisitorsFromDreams
There are also some balancing tweaks, more dynamic combat and new battle animations on the way to make Episodes 1 and 2 feel fresh for those who have previously played them. :)