Maybe it 's just me but I've always thought of this kinda things as the paint job after all the body work [carshop metaphor].
Anyways I like a pipeline of -

1)building the code frame work
2)build levels and environment code
3)level lighting
4) build simple meshes and character code
5) then level textures
6) build detail meshes and character textures
7) then effects (with code)
8) and finish with gui/hud.

This lends to team work but will also help from putting the cart before the horse. I'm not saying your doing anything wrong. Just how many times have I started one project only to have it morph into something else? (especial when work for a beginning designer), anyways I think you could make the years scariest game using the super Mario world and meshes.