Bowies_Wanger

OK, compositionally, it works. You could crop the left side a little. That might make it a little better, might not. Your choice, but photoshop has an undo button.

I'd mess with the curves a bit. I mean there are alot of directions you could go with it. I think greyscale would look really good, or signifigantely reducing the saturation, but that sort of thing is almost standard for the "rusted out pices of metal in the woods" shots, and there is something I like about the high contrast nature. Maby go into the individual RGB curves/levels and give the 3 main elements (green foliage, sky/windows, rusted out roller coaster) different tints? Like lower the intensity of the green, add some brown to the sky and make the roller coaster come out more orange? I mean there are a million different ways to do it, but you have the proportions of one element to another down really well, it's just all about getting the colors and values to work.

EDIT: I messed around with your image in photoshop, PM me if you want to see it.