Here is one of my Blender 3d illustrations from a book called Let’s race available for free on iBooks Store. I would be very happy to know what you think.
I love the character of the cars, they look genuinely happy and having fun. And the lighting is really good too in my opinion, it adds even more to the cartoon feeling.
In the very best “Thomas the Tank Engine” tradition, these are very nice images and a well-designed, stylized world with lots of primary colors. The “mushroom trees” are a very nice touch. Well done, indeed.
I am grateful for all your comments. Especially when they are so positive 
thanks.
I really like the images. If the story and puzzles are as good as the pictures you ought to have a best seller. (or best free-er?)
Very good work on these man! they look like stills from a program on a childrens TV channel
Top quality production! 