It seems to me that you aren't quite yet working on a pixel level. Only the ground and the closest trees resemble pixelart.
When doing pixelart, you have to consider the position of every individual line, you don't just use lines and fill with colors.
And, you absolutely can't use techniques you would use in other digital art, like the blurring on the background trees and the wolf.
(Tip: use a color that's either darker or less saturated for the background trees, so they don't clash with the foreground ones)
So, don't just use lines, and blobs of color fill. That's only half of the work.
Afterwards, you have to consider the light and texture, and modify the pixels accordingly, in an individual manner. It's a lot more work, but it's worth it!