Looks really good, I like the shadows, and the dust behind the motocross. I'm satisfied with the ragdoll, it acts realisticly, don't change anything ! (perhaps collision between the bike and the ragdoll...)
You say you need an artist, but for now I don't see what's wrong with the graphics... just add a mesh to the bike and the ragdoll and everything should be fine.
Good luck in finishing/releasing this one !