1) add 'lighting' effects for the bugs based on the sun position
2) fade the bugs shadow near the bottom of the picture
3) add plant n signage shadows
4) add a gradual tone for the sky
5) make the sizes of the birds different to indicate distance
6) make the ground a little ruggard, now too 'smooth' and straight

nice concept

Thanks for your suggestions aheman!
I tried to implement at least a few. I am not sure if adding the grass was a good idea.

Very cute, author. The bugs' construction reminds me of the old Cootie Bug toys.

http://www.canadiandesignresource.ca/officialgallery/toys/build-a-cootie-bug-game/

Thanks pearlie. That's true, I had the German version of those toys. They looked a little bit different but the main principle was the same.