Personnaly, i think that's the graphics primarily that make your FPS look professionnal
If textures are really good, and if you use shaders or normal maps, you'll have the professionnal look !
Professionnal don't mean a lot of things , even lot of games with simple graphics (not really rounded polygons) are sold today !
I think you say professionnal to say a completed game that is selled in fact ?
There are professionnal AAA games like the last Wolfenstein, that are professionnal looking, but linear, really corridor run and gun game, with on real worked environnement, with really poor basic gameplay.
That's only my personnal opinion on that game
, some people like it i think!
