This is great, but...
I think your style needs some refining. Nothing entirely new just some cleaning up and stuff. I know you struggle with digital art just as much i do, its awkward on for some folk. One thing is the lines, they are a bit choppy and tasteless, i think you can add a little more and a little less here and there. Then the coloring, which i know is the digital majority of the image. It lacks atmosphere, nothing is really drawing all the air of the image to make it feel like its breathing. And lastly, detail is missing in some places it should be. Like the bottom of the support beams for the tracks and minor details in places like the bark of the wood that could have gave it some depth. All in all i like the picture though, i just feel it was a bit rushed even though you chopped away at it for so long which may be the entire issue. But i know your experimenting and that takes some steps like these.