Thank you for playing, the doors are real, I just blocked them off for now as there is nothing truly built up yet in the second area.
I do agree that the boss is a bit of a difficulty jump, mostly because of its phase 3 attack speed increase. Guess I can be happy the regeneration system was not yet implemented for the boss, it might not have been beaten then.
Thank you for your feedback and I am glad that it was fun, please look forward to future updates, there is even a minotaur boss planned.