Why does the game window go blank when the mouse is moved outside of it? This usually happens at the worst possible moments. Bad idea. Why is there one sound for both hitting and being hit by the boss? Bad idea.
Very cool to see a shooter with the traditional fantasy RPG elements instead of spaceships. My only suggestion would be that the monster death sounds are somehow annoying. I think the problem is they are too long. Sound is not very important to me usually in games but this was hard to ignore.
Dreadmane is semi rare. Easy to kill if you use your special power, which you can find it at the end of the row of buttons your attack button is in. Special power can only be used every 30 minutes, so do the challenge in steps.