This small had a severe need for change. The floor had a lot of scratches, floorboards for replacement, and other issues. The best and cheapest solution was to make a new floor installation. This time it was solid wood floor fitting with finished floorboards.
The most important thing, in this case, is to create a perfect sub-floor preparation with an insulation pad and fix all small stuff. The whole job took 1 day, and the room is ready to use.