I think the soft, not intrusive gradient give a great and unique look

Yeah.  If you centralized the sun and added clouds or something, this would be much better. 

I thought you were gonna change the gradient-sky? Tsk, tsk. Get rid of the gradient and this would be soooo much better.

Oops, I meant lack of top tree branches. Sorry for dp.

I'm back with more critique. The trees top branches...I don't really get. And I forgot to mention, that you pulled a water color look off nicely.

It's nice, just as everybody said, lower the color and avoit using gradient tools. it would look nice for a web page layout

Nice effort. The gradient nulls it being pixel art. This should be revised.

I agree with the criticisms below, but I also really like the composition and palette! You've created a really nice mood with that stuff, and with the movement implied in the leaves. Clean up the other little problems and this can be a great piece.

Hmm.. To many colours, probibly on everything and especially on the sky XD.. And the dithering looks like you used the paint spray can, anyway pretty ok work ^^

It's because of the gradient in the top right. Fix that, and then I think it's ready.

I counted 97 colors for this picture which is a lot seeing that there are only 5 or 6 different hues... Moreover the dithering you did seems a bit messy ...