A lot to like about this one. A fully functional game loop. 3d boss fight with a lot of spin! That fact that you had the time to add a customizing option is fantastic.
If there is one thing I could wish: Do not default to the highest difficulty level, it can be very frustrating if you never played the game before and I did not expect a game to default to this. Other then that there is not a lot I could ask for.
Well done!