The story is soon complete. I am currently working on the endings. After that, I need to try the story from start to end and do a full bug fix (because I always come across a lot of things to fix during my first playthrough. Don't think this is an exception).
The only new thing I may add before my playthrough are upgrade items. Some of the encounters in this story can be pretty diffuclt. I had some of those hard moments in Final Revelations as well, however, you could find money and buy extra supplies to make it slightly easier. It makes no sense to add stores in this story, however, upgrade items similiar to F.E.A.R could work. Altough they will be carefully hidden, so exploration is important in order to find them.
Example: One secret item will slightly increse your speed permanently. Collection another item will fully restore your health and sanity at the start of each map, etc.
Another thing I'm going to do is delete everything I no longer need, and perhaps things I think are not important to the story, because as of now, the size of the story is pretty big. Not enormous, but bigger than my previous stories by far.
The story ended with 21 maps. How long it will take to play it remains to be seen.