You are Gordon Freeman, or, as only a few people know, Roland Blackheart, a SAS officer with legendary skills. You were working for a foreign government, after you had been sacked from your original posting for disobeying orders.
A single player map for Halflife
Make sure to read the readme file.
Small, furius, and there is no end, just a constant roof-top war. see how long you can live, then see how long you can keep your bodygaurds alive. Just grunts trying to beat you up.