I've been playing this game for a good 6 months now so this is not your average rushed internet review.
To begin with, this game looks like a smooth Tom and Jerry cartoon in action. Even though the source engine is single threaded, and the tech is basic stuff by today's standards, the artists at Valve did an awesome job with the color palate and models to produce clean cohesive visuals. The result is an awesome looking game that runs all max @ 1920×1200 at a solid 60+ fps on my rig.
The game features 9 different classes categorized into Attack, Defense and Support, each of them having their own set of advantages, disadvantages, unique weapons, characters, nationality and their respective accents. You have your standard control point, capture the flag and death match (Arena) modes. Personally I think there are other games with better gameplay for these modes. What TF2 has and no other game has is a mode called Payload, where the blue team pushes a cart from 1 point to another while the red team should try and prevent them from doing so. This is an awesome mode since the emphasis is on team work and hence needs a good mix of all classes and people working together.
The sound design and effects are excellent and the voice actors deliver their lines in fitting style. Each character has his own unique taunts and personality and this makes things more interesting.
In this age of gaming where games are primarily designed for consoles in mind, I can say that TF2 has been designed for the PC – unlike games like COD 4,5, Halo 3 etc. that have kinda flat game play where you just keep your crosshair at a certain vertical level and just strafe horizontally on your controller. TF2 has crosshair movements all over the screen, up down left and right and is a delight to play on the keyboard and the mouse.
2 things I dont like about the game – it uses an achievement system to unlock weapons and payload mode needs more maps.
To top it all, Valve constantly supports this game with patches and updates and there are heaps of low ping servers with people playing pretty much all the time.
To summarize, TF2's game play needs a bit of skill, has a bit of luck mixed with bucket loads of fun. This is a great PC game that every PC shooter fan must have.