By Pixie
If you feel burned out by all this, leave it in the backburner for a while. After all, it's just a hobby
That's very right. Sometimes, a break is even an excellent things, offering some fresh ideas and perspective. I tend to go working on something else (very different if possible) when I got bored or lost motivation. And usually, I come back on the project with a renewed envy and new ideas.

Concerning you good example, they added the shadows to give the feeling of 3D and break the flatness. You surely can obtain this kind of result in Wilbur (though my method isn't probably the best, as it is very long).