Quite curious
Did you start by clicking start or loading chapter 1. Cuz loading chapter 1 does not work.
And uh, in terms of editing the savefiles I believe these are the instructions as posted by the author:
Go to
C:\Users\[USER]\AppData\Local\Otter_Tail
and set secret_flag4 to 0 or 4
I have not messed with the savefiles myself and Im afraid I will not be able to assist further if these 2 methods still do not work.