I would like to say something about the final secret in my opinion(do not flame me pls :)))))

So did u notice that if U choose arcade mode at the start screen the cam will floating into the flameing tunnel and the dragon logo sliding in the wall. (got it? Sorry about my english )
So I noticed that U can find a similar dragon-gate in moloch's lair. Maybe somehow U can unlock it ...open it ....hm???