How to setup a 'flat' material/texture like this reference image

All

New to Blender so uncertain best way to describe what I am asking. In the image below (an ipad game) the sheep/trees have a flatish material and texture, how would this be done in Blender. Any thoughts appreciated

http://obamapacman.com/2010/12/christmas-aliens-stole-ipad-xmas-sheep/

I think I would start off by setting the specular intensity to 0.0, emit to 0.5 and diffuse to 0.5. Then try ambient occlusion for lighting.