The left version looks better I think its like a good balance between the new art and getting closer to the previous tone but personnally I dont mind too much, I actually like having some regions less gloomy than before (There is a little bug walking on my screen its annoying...) any way what where I saying? xD I think the left side for forest is great, for other regions it may depend, like the cabin could stay as it is because its home and you gotta feel safe at home but sewer and Swamp could use a little more i guess because the vibe there is more prone to it (now the bug is flying around me always passing between my eyes and my screens, she better stop or i will activcate Rambo mode agaisnt her) So yeah, I guess its a qustion of which regions should inspire what feelings according to previous version and the music of regions can help having something that match the tone of it.
The more I look at it and yeah the left side look really great in comparison of the right side which look too much vibrant, especially the green which pop a lot on the right side so yeah difinitely the left side is better (Alright im done, the bug just has made her last lap, because now i wont rest until she fall asleep, difinitely...)