Since you're asking for critiques, I'll bring critique:

- The 'cloud' covering the top-left side of the moon looks pretty odd colored, or rather, it's simply too saturated with color, considering it's a night scene.

- The rock (the one the girl is sitting on) is.. weird? It looks like you basically pasted a texture on a shape that would resemble a rock. That doesn't work. Textures should be the last ultimate resource when drawing anime-like background. Pretty much all of the textures that you see in that kind of background are usually achieved with a simple grainy/spatter/dotted brush, something that's among Photoshop default brushes, in case you didn't know. With proper celshading and that brush set with the proper opacity and flow settings (according to what kind of lighting, depth and detail you want to give it) you can obtain a far better result than just 'filling' a shape with a texture most likely grabbed from a stock photo. Or even better, you could simply draw the rock and do the basic cel-shading, most of the background artists in anime industry don't use textures anyway (only for camera close-ups) in most cases anyway.

- The farthest tree needs to be adjusted as well. As you can see yourself (since you drew it XD) you rightly and correctly blended the vegetation that is on the other side of the lake, coloring with a sublte purple colour. Now why didn't you do the same for the tree? As it's shown you placed the tree behind that line of vegetation so that hints that most likely the tree will have a similar level of darkness (making it blend with the background) as much as that line of grass has. It kind of makes no sense to have a correct blending and then suddenly a tree that has the same lighting as the trees that are closer to the girl. Get the idea?

And that's it. I don't know if I pinpointed anything I could, this is just pretty much what I noticed at a first sight.