Theoretically solid, technically flawed.
The graphics are just great, I really loved this animated style mixed with the insane chaos, it was like you were watching a cartoon on drugs. The graphics fit perfectly with the silly humor in this game; all the character are stereotypes, the taunts are very retarded and some of the power-ups are objects the animanics would come-up with. A random situation I ran into was when I played as a fat Russian (voiced by an American who tried to sound Russian), firing a turret I was carrying the same way somebody would carry a shotgun when suddenly my friend shows-up and jumps over me after drinking cola. Makes sense?, no, that's why I love it.
I already mentioned that this game in incredibly chaotic and I actually really like that. Nobody is playing to win the game, they are just playing to fire at enemies and mess around. The goal is to either capture areas or capture the flag, but while the area-capturing is alright, nobody captures the flag (or intel as this game calls it) unless they are grieving. Yes, you are grieving in this game when you are sticking to the rules. Most of the time it's just shooting, shooting and more shooting.
Most of the classes are really fun to play as and require a different approach than others. The Pyro for example carries a flamethrower, but lacking a long-range weapon forces him to stay in close quarters and surprise his foes. On the other side we have the Engineer which can set up mini-bases for the team to move forward with. There is a class for everybody in this game and you'll never find yourself stuck with a character you really don't want to play as.
The large amount of achievements may make this game a little too large to do a 100% on, but it does make sure you are occasionally rewarded for playing. Achievements vary from simple tasks, to grinding kills and all the way to insane accomplishments. This meant that when I started playing I was able to get all the easy ones, as I grew better I would start getting the grinding achievements because of the time I had put into the game and now that I am quite skilled I can start getting the tough-as-nails achievements.
Lately the game has gone free-to-play and personally I am quite happy about that. However, I do feel that when you make the switch to F2P, you should properly reward the people that paid for it and that's where Valve fell short. The only reward you get for paying for the game is a hat, one of the million hats that are in the game already. Call me a whiner if you please, but when I am given a hat that I instantly lose in my inventory filled other clothes, then I am not awfully thankful.
Like most other games Valve also opened up a store in which you can buy items with real-life cash. I would be okay with a store where you can buy even more cosmetic items, but Valve also decided to put in ALL the weapons you can find in the game and this has genuinely affected gameplay. Let me be very clear: I will never buy items from in-game stores with real money, I think it's cheap and lazy. This decision however gives me a disadvantage compared to the hundreds of people who do not care and got all the best weapons the game has to offer. To challenge me even more, the game constantly gives you chests which you need to BUY keys for in order to open.
Let's put the switch to F2P behind us for now and talk about the core gameplay. I have always disliked the way servers work in Valve games, they never have any official servers hosted by the company itself, so we are left at the mercy of the individuals hosting these servers. I have no problem with connecting to a server to evaluate the settings they went with, this has occasionally led me to some downright awesome servers that I have played on for years, but what I do have problems with is that any server can automatically download files to your computer. When you connect, the server sends all its music files, documents and game files to your computer and we can assume you are not always aware of this.
Talking about files, the game has become quite bloated by now. What started out as a pretty fun FPS that come with the Orange Box has become a 11GB giant that is filled with insane amounts of needless content. The constant patches that bring new cosmetic items to the game may be fun for some people, but whenever I have to re-install the game, I lose several hours of my time. For some reason I can't access my favorite servers anymore either, because they are using older versions of the game and this makes me incompatible.
Those who paid attention probably noticed that I said "most classes" are fun to play as, that's because not all classes are like this. The spy may seem like a good addition to your team, but the learning curve is a dozen times steeper than those of all other classes. The spy can disguise himself as the enemy team, become invisible, instant-kill enemies with a backstab or sap enemy buildings to disable them. Invisibility may sound cool, but even with the best invisibility watches in the game, your invisibility meter will drain insanely fast, so you will always become visible again in the middle of the field. Disguises also rarely work because all players are hardwired to check everybody for been a spy, so even when everything seems okay, you will still get burned. Backstabs also automatically make your disguise go away, so when you stab an engineer his turrets will kill you before you can do anything back and if you sap the sentries, the engineer will pummel you to death.
The Demoman is also useless for everything aside from spamming. All his weapons have timed detonations that, while been rather strong, leave him without a direct attack. Even the Heavy and Engineer have a shotgun to help them when their class-specific roles can't be fulfilled.
The Bottom Line
A few days ago I saw a new review on this website for this game, the person who reviewed it was clearly a big fan and I am glad he's having so much fun with a genuinely entertaining game. However, I do think his review was to biased, as he claimed it the game was perfect while it technically isn't (though theoretically you could say it's flawless). While it seems like I am mostly complaining, I do really love this title and it's one of my most played games of all time.
If you are looking for a high-quality F2P game, then this should definitely be your first (and perhaps only) stop. Fans of the FPS genre should also look towards this gem. If you prefer a more structured kind of game though, then I am sorry to inform you that TF2 is most certainly not what you are looking for.