Halp

I'm procrastinating doing things, so I might as well start with this one.
I'm going to lightly touch the stuff that was mentioned by other users and then go into detail the things that I feel are unmentioned but need attention.

First and foremost:
Dem leaves girl. I know you know, but they really hurt this picture. Not the fact that they aren't detailed, but that they're everywhere and really bright. It's hard to focus on the main point (the cat) with them. try implying that they're there next time but a few transparent leaves in the foreground and then maybe a few off the the side?

On that note, I can see the effort you put into that trunk. It's nearly perfect. All you had to do was make the contrast between the light and the dark a bit more noticeable. Otherwise, it's pretty great.

Let's move on to the cat.
Pose and anatomy wise seem to be a good point for you. It's not perfect, but I've seen your later work and you do seem to have a good grasp on cats. However, I'll just point out here that I believe if a cat was desperately trying to stay in a tree, they would use both hind legs. In this case, the other leg kinda looks a little off-putting.

Your lineart for the cat seems fine until you notice the tail, where it seems a little messy. Maybe a little less spikes? Otherwise, good job. c:

I saw that you already explained that the flower was laziness, so I won't get into that.

As for the coloring itself, the feet markings shouldn't be that symmetrical. They're a bit more jagged and I think they take a more V shaped characteristic. just something to keep in mind.
I like the colors you picked, the go very well together. I would have liked to see more detail in the eye, but I can't detail myself.
However, you do have an issue with your shading. I saw that you had said that you liked dark shading, and that's all fine and dandy is you know where to put it. I 'm having trouble with finding a clear light source, and like I said with the tree, I wish the contrast was higher.

And now for the final bit: the background:
I think you chose a bit too bright of a blue, but that's just me being picky. Really, the only problem here is the clouds on the bottom. Clouds are really high and really far away, so you would have to be in a really tall place to be at or over the level of a ground in any perspective.
(as you can see here: [link])
Even in high places the clouds should be above you at all times.

In any case, I hoped I helped.
Sorry if this was too blunt.