So I found all keys, treasures, including the sword, but I defeated the count with two holy water arrows (had to make a run from the fountain). The game didn't register my kill and failed to end properly. Maybe the intended way was to sneak into the treasure room to get the sword and then duel the count on swords, but hey...

Anyway, the mission is OK, given it's age. I don't particularly like missions where you need to scavenge for equipment, and in this case you go for the kill without anything to kill it with, which is stupid. It maybe deserves 4-5/10, but given that it didn't register my creative kill, I'll give it 3/10.