The game is beautiful, characters, background, objects, lighting, everything fits nicely together. The music is unobstrusive, supports the atmosphere nicely.
My biggest issue - what caused me to almost give up prematurely on the game - is that I had no idea what to do and had to run around a lot to figure it out. Fortunately, this could be very easily improved by giving more contrast to areas where you can and/or are expected to go and areas that are just background. That way it would be more obvious what the different paths are from the get go.
I would also change two things regarding the paintings. First, add some indication while the player is in the process of lighting them on fire. I wasn't sure they are the paintings I was looking for because it looks like nothing is happening for the 8-10 (?) seconds you are interacting with them. The other thing that would be useful is an indicator of how many paintings there are and how many have you already set on fire (or just how many are left).
Overall, great visuals, nice atmosphere, fun to play once you figure it out!