At first I wanted to pint out the light bleeding on the walls, but then I thought, fuck it, nobody'll notice that when it's animated. Turns out I did notice after all
What I mean are these spots:
Usually caused by misaligned normals or polygons in combination with Gi or Ao, if I remember correctly.
Next step I would suggest, is making it look more dirty and spooky, maybe?
Nice work nonetheless.