Yes!!!
I did it on Friday evening. It took about 4 hours!
The result – I think it’s very good. I ask the organizers to check my save file. If any questions arise, I can answer them because I still remember how I completed it. :)

Oops, I missed the point about describing the final battle.
The description is as follows: Press the "M" button (attack with the hero closest to the enemy on the last computer-controlled hero). Press the "A" button (autobattle). That’s it. :)