Well in only one picture, it's like look like an old FPS.

You should work on concepts before :
planning where the action take place, what are the surrounding,
and design a better architecture tha simple flat walls.
- Shader with too much specular !
- Rain looks not good, perhaps it's better in movement ?

Juts my advices, it's your game and indeed you are not
a company with 4 or 4 skilled veterans working on 3D Game
art

For the moment it's empty, you should show more when you will have better complete and worked level section and some
player interaction.