Environment choice for a color-only objects My question will definitely sound incredibly noobish, but I started to play with 3D graphics and Blender just a few days ago (after a month-lasting struggle with OpenGL basics) and I've run into trouble. 

I have "created" a nice small bunch of models for a 3D game, determined that I wouldn't use a single texture for the appearence of the objects. This is what they look like:


Right now I'm trying to create some environment (terrain, lights...), but all of my previous attempts have failed.


I tried to create a hill without modifying it´s color. Result: the hill is unrecognizable, it has just the same color as everything else. 





I played with Z-transparency. Result: better, but nothing delighting. 




Instead of trying and experiencing failure again, I want to ask: is there any way I could create (a visible) terrain consisting of hills and valleys without using textures? Are there any specific ways of doing things when doing "cartoon graphics"?
enable Ambient occlusion to get better lighting " you should lower the light source intensity "  
move the light source to get the shadows where you want
use proportional editing to create hills 
add decimate modifier to get the LOW POLY look