Well, I finished playing it and it was an overall enjoyable experience: contradictions weren't too hard, and Vladimir was an enjoyable character.
As a reader, I was kind of confused about the ending of part 4 because:
A. No verdict was given (I'm assuming because you wanted it to seem like a tie between the two parties, right?)
B. At the end, the villains kind of left me feeling... empty, I guess? I was expecting a bit more backstory on Eden than the breakdown infodump, honestly.
C. Otherwise, I think you should focus on building them up your characters a little bit more, like I'd have liked to know a bit more about Suntome and T.N.T.