An interesting and unique shooter that any FPS fan should try. Read on.
The reason why I was not impressed is because I wasn't good at it at all. The learning curve took awhile, but I was adamant and I wished to be good at it. While playing, I felt as though I would enjoy the game if I got good at it. I stuck with it and now I'm fairly good, if I may say so myself. It's been a rewarding experience to say the least. After going through the newbie days, it is a very enjoyable game.
I really love the classes in this game. None of the classes seem too overpowered or underpowered. They keep them all equal in their own ways. Different people have different favorite classes. I, personally, am well rounded. I'm not "pro" or anything in any class, though I am sufficient in each class to get the job done.
You will really feel like Valve put thought into each class. For example, the spy class... Primary gun is a revolver pistol, secondary is a zapper, backup is a knife. Also armed with a cigarette case. The pistol is a normal pistol for when the spy is caught and is in a combat situation. The zapper is for when you have successfully sneaked into the enemy base and you can disarm an enemy building like a Sentry or a Dispenser. The knife is for when you sneak behind an enemy and can one-hit-kill them if you have a successful backstab. And the cigarette case allows you to disguise yourself as an enemy, so that you can blend in with them for a successful sneak. Along with all that, the spy has a watch which turns them invisible.
And that's just one of the classes. All the others are just as great.
Don't be deterred from this game thinking that there is no class customization. While the customization isn't as big to it as it is in Call of Duty, you can still customize the class slightly. Occasionally, you unlock new guns as random drops which can be added to your class. You can also add hats to your characters, which doesn't really add to the experience, but doesn't hurt, either.
You can also craft items and make new ones. This is very hard to explain, but might I suggest a Youtube tutorial on this? Just search for one on Youtube about crafting in TF2.
One thing that I didn't like about this game is that in the PC version, often you will see a server that says something like "24/26 Players" and you'd want to join. You join the server and there turns out to only be about three players. That's extremely annoying, but only a few servers do that.
Another thing about servers, nearly all of them are VAC Secured. Hackers are rarely found, at least without them getting caught very quickly.
Lag is at times found, but not too badly. Not really any worse than a Halo 3 match in most cases.
The maps are so-so. None of the maps are bad, IMO, but not many of them really stand out, either.
The gametypes are fun. Simple things like Capture Point (like Domination from CoD), CTF, which uses an intel briefcase instead of the traditional flag, and other, more deep gametypes.
I can't really blame Valve for this, but one thing that is a downside of the game is "Spy Checking". Now, as I said earlier, spies can disguise themselves as an enemy and sneak in. Well, what is now the norm is to shoot each and everyone of your teammates, since Friendly Fire is turned off. This way, if it really is your teammate, it won't do any harm, but if it is a spy, they will bleed, and you should notice it. It just takes away from the experience as a spy, where it is nearly impossible to do a successful sneak unless your teammates just plain trust everyone, which is uncommon.
I also don't recommend this game to you if you are under the age of 12 or so. The community of players are for majority older people closer to 20-30ish and they don't take too kindly to young people. If you are 12 or below playing, I highly suggest to not use voice chat. I, personally don't have a problem with younger gamers, as long as they can stay mature and play the game correctly, but I know that not everyone is like that. I can't count how many times I've heard players mock children in servers. So, just use voice chat at your own risk. If you're 13 or 14 or so, as long as your voice is somewhat deep, then you shouldn't encounter a problem.
In gist, I highly recommend this game. It's great.