Pros: Layout seems like a good one.
Cons: No lights. Add a light_envirioment.
If you use dev textures, use ONLY dev textured things. The bridge seems stupid, as it is one of the only things, that have textures.
Improvements: Add lights.
Make EVERYTHING textured, OR dev textured.
add a 3D skybox.
Notes: Try to add real textures, It is so much better looking. =)