Intense online shooter that will have you playing over and over again
The main difference form 1.6 is the massive difference in graphical presentation. Now, the characters and maps are more realistic with the latest maps including HDR Lighting, adding a great deal of realism to the experience.
As always in the Counter-Strike series, Source puts counter terrorists against guess who…the terrorists. The main objectives are bomb planting and hostage rescue. (As if you didn't know that already). Where Source differs from most online shooters is the never ending number of updates and improvements made to it by Valve, moving closer and closer to the goal of perfection. This process will never end of course but it is nice to find a publisher providing for the players after they have their money.
Another difference is the modding community that has been more present in CS games than any other. Amateur developers can create games of their own based on the CS framework and this adds to the life of the game considerably (if modded games are your thing)
When in-game, you buy your weapons at the beginning of each round and set out to destroy the enemy. That is not so say you can run out there like a headless chicken because this will almost certainly result in your death, which can be frustrating as you will have to wait for the round to finish.
The guns control more realistically than some shooters in that you will get nowhere by holding you finger on the trigger. Precise shots to the head and chest area will bring down opponents much more quickly and each gun responds in different ways to how you use them. With SMGs you can be forgiven for a bit of spray-and-pray as they fire at high rates, but are not the best for long range, where an assault or sniper rifle if preferable. The game is probably not for first-timers, who will just be demoralised by the number of decent players out there.
Some may find the idea of having to aim properly a pain. If this is the case then CS:S is not for you. Others also complain that gameplay has taken a step back from 1.6 but it must be remembered that the original CS was running for a long time and so has had more updates. Some argue that the AWP (sniper rifle) is overly powerful, but there are many servers that disallow this weapon. The odds are that if there is something about the game you don't like, there will be someone else running a server with settings that are more preferable to you.
Despite the few criticisms, Source is one of the best online experiences ever and is well worth its price. The graphics are sharp and ever improving, the character models look realistic and new ones are being created all the time, and the gameplay is more satisfying than your general run-and-gun shooter.
Highly recommended