When looking at the screens, one can tell that they must have been made towards the beginning of the game. Everyone's level ist one or two and the monsters are those from the initial parts of the game. Sure, it's possible that Lachsen made a change to the plot in some way, but it is far more likely that these are (admittedly very convincing) fakes.

The thing that the screens lack which would, in my eyes, verify their authenticity is one of Yahenru's attack animations. Those would be far more difficult to fake than a simple "standing-pose" and a face in the main menu.