The castle was animated by Dracula's evil magic. While the games are vague about how all that works, it's been pretty clear that you need Dracula's soul around to make the magic of the castle itself work.

Now, they're in a summer home (not the castle proper), but without Dracula floating around, even the other mansions are less... spooky. No ghosts or what. Just, apparently, one stray rabbite.
 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.