During the second battle with Colonel Mueller, I encountered a critical bug.
Mueller has not reduced his health since the first fight.
Why did I even decide that it should have decreased?
That's why:
Not only could I not defeat him for 9 full cells of concentration, so even after bringing his health to a critical level after that, he did not lose consciousness.
And as you might know, uncharged hand attacks do not harm the bosses in this regard from the word at all!
So at this point, I physically can't spare him!
Unless I copy the famous scene from MGR where Raiden unsuccessfully tries to defeat Senator Armstrong.
And neither restarting the game, nor rebooting the computer, nor even reinstalling the game could overcome this bug.
In the discussions I saw a couple of people who faced the same problem, but it seems that they could not find a solution to this problem either!

The game is extremely cool, but because of this bug, I will have to drop the game (and not far from the final) because of this stupid bug.
So if you liked the game too, but haven't gotten to this boss yet, well...
PRAY