It's nice to play a game that doesn't just have a CD track droning on in the background. Atmospheric sounds like the distant honk of a car horn or a dog barking give a sense of life going on around you. Right from the first mission it had me hooked, wanting to find out what forces were behind the city's anarchy. All I will say is that they are a strange bunch. Playing Urban Chaos gives you a great feeling of really being in a run-down city.
Litter blows through the streets, which are alive with people going about their business.
There are some annoying glitches in the game engine though, where some platforms are impossible to walk on to unless you jump or even back flip on to them. The lack of networking options may be a factor in your purchase as well. But to be honest, with single player gameplay this good, you won't be worrying.