I agree with Xion here. While the current thread is a bit messy, making it mandatory for someone to open a new thread to display line arts is a bit much I'd say. Have two threads for coloring/lines would be a great solution to that. Since most of the lineart that is colored, is done in spare time and for fun, it would be counter-intuitive to turn it into something more. There are already people who make individual topics for linearts they've colored, and I think those who do them seriously and want critique will do that.

I really like the colors in this piece, very lively.

I feel that the hud doesn't fit in very well with the rest of the picture. Same goes for the character. Everything else is very bright and cheerful and unique, where as the hud and character look rather uninspired. The AAing on the green circle kind of hides the fact that it's a circle. It looks more like a stop sign/octagon to me.

The tiles look a bit repetitive, as Terley said. Perhaps you can create a few variations to tile together. They also lack depth. the highlighting/shading looks to be more of a pattern than highlighting/shading. Which isn't necessarily a bad thing but it looks like it's struggling to find it's place.

The background mountains do a good job of showing depth though. Perhaps you can use some techniques from the mountains on the foreground stuff. The clouds look cheerful bt kind of like boulders. Maybe go for some softer colors or maybe softer definition.

Overall it's a pretty good piece though.

Once again, we have an update. This time there are a lot more objects and things to be seen. I still have to populate it, and probably add a few more knick knacks in it.

There's now a rough draft of the mock up as well as some modifications to the tileset.