Let me start off by saying do not buy this game.
It is a fps and not the worst one I have ever played by a long shot but it is really short. There is no online to speak of. The weapon reload & cover system are poorly done.
All that being said the in game voice is done by Mickey Rourke and fucking hilarious. Lot's of F bombs among others but some funny shit none the less. At one point I moved up behind and enemy and threw him off the bridge. The commentary was something along the lines of "President Reagan sends his regards".
This game is supposedly based on Richard Marcinko's books. Marcinko was the first commander of SEAL team 6. Don't know how much of his books are fabricated but he certainly has been in the shit.