Larger scales tend to feel more satisfying to me - I also like working on pieces that I can come back to months later to improve upon after having dropped them for quite a while. I've done some things at smaller scales, but I tend to get bored and feel as though I'm not improving as much when I do :P

I like the colors, and the scene is cool. Like you mentioned, it could use tightening up. Perhaps work at a smaller scale? So you're not overcome with so much work that way