Posted 26 May 2007 - 09:05 PM
Okay, lets see.
No, there is no actual demo of the game. However, Valve has been starting to offer 'guest passes' for some games for people who own the games to give to people who want to try that specific game out, but I don't know if they have added guest passes to Counter-Strike: Source yet (I'm pretty sure they've done Day of Defeat: Source though). Have you played the older versions that run on the Half-Life engine, 1.6 and Condition Zero? Counter-Strike: Source (CS:S now on) has taken some features from Condition Zero (CZ now on), such as increased grenade damage and grenades wont hurt you if you're behind an object.
The relationship between Half-Life(2) and Counter-Strike(Source) is that they are run on the same graphics engine and will feel kind of similar when played because of which. Still, Half-Life(2) is a single player game while Counter-Strike(Source) is a multi-player only game (with the exception for little single-player missions in CZ).
There are some problems with CS:S that people complain about though. Some people claim it is too easy and because of larger hitboxes, headshots can be popped off pretty quick. Still, if it's easier to get kills, shouldn't that make it harder because it's more difficult to survive? Whatever, mainly CS:S is CZ with Source engine graphics and other tweaks to weapons and such.
Hope this helps,