No story, no music, no plot, no depth. But it's addictive as hell
Counter Strike Source is a realistic tactical shooter so it will be confusing to those who are new to it. When I started playing about a month ago I was frustrated that I would spray over a guy with an smg and only give him 10 damage while he killed me with 2 headshots with a rifle. Now that I've been playing for a month I have crawled from the dark pit of "Noobidity" and am now as good as most people you'll find online, it is easy to give up but once you start to learn and the moment comes where you realise that you are no longer a confused noob then there's no going back. Those who say this game sucks only hate it because they can't play it.
Graphically it is not as "shiny" as games like Quake4 or FEAR but what you will notice is how "real" everything looks. The lighting, the shaders, the bump mapping, it is done subtly and it looks very natural. The textures can be blocky sometimes but it's easy to ignore with the quality of the bump mapping, lighting effects.etc The gun models are incredibly detailed, the animation of everything is smooth and natural, it will play fine on any recentish PC as well. All of these things put together make this game look just as good as any other recent game out there.
The audio quality is great, all the weapons have their own distinct sound and they all feel really solid and powerful.
This is a great game and despite it's lack of Single player (except in the form of bots) is still very good value, even with a 56k the game will be more than playabe on a local server. If you enjoy this game from the start there is a good chance that you'll keep on playing and you will get in excess of 300 hours out of it depending on your free time and tastes. As the game never ends there is no reason for you to stop playing. You may get over 1000 hours out of it, I don't know