It looks like an EXTREMELY COOL work in progress. I'm guessing that you're still fleshing out the background layers and cleaning up the tree (but only a little bit). The bridge looks beautiful. If you are actually planning to keep the background tree layer that way, I say it needs more definition.
I'm not sure what to say about the characters as they are. To me they seem too small and some of them almost have too much definition in contras with each other (I'm not sure if that's what you meant before). I think it's good for the characters to have contrast between background layers, but every character should feel cohesive. If you want to have more detail, they should all have the same amount of detail. And as I said, I think they should be a little bigger.
Finally, I think your color choices are very solid. This is especially obvious on the bridge.