Adding Passion to a Design

This a a perfectly acceptable drawing. After looking at it for a few days I got really tired of it and sat down to analyze this drawing to figure out why.

First of all, there is no value shift - all the colors are basically the same, no variation of dark and light.

Secondly, the green and brown are half the page and the blue is the other half. In art there is a "rule of thirds" which tells the artist to divide the page into third horizontally and vertically and place interest points on the intersections of the horizontals and verticals. That wasn't done in this drawing, to its detriment.

So, I got busy and doodled on this drawing to try and make it interesting to look at.

What do you think?