It's Team Fortress - only better

Valve has taken the proven concept of the original Team Fortress, and simply evolved it to the next level. Basic things have not been messed with - it's still nine classes and two teams on fairly small maps, and neither side is taking any prisoners. Everything that made Team Fortress great all those years ago is still here - just prettier, more polished and in all possible ways... better.

Some details of the gameplay have changed slightly. Some classes have changes in their weaponry, the universal supply of grenades across all classes is gone, the Medic no longer spreads plague to the enemy team and the Demoman has lost his explosive packs - all good changes I can wholly agree with. Despite the changes, it's still feels very much Team Fortress.

Medic, Engineer, Spy

The Medic is probably the class that has changed most. He has the syringe gun as secondary weapon, dealing some rapid-firing pain up close, but the main thing is the new healing gun - target a team mate, and the gun heals him while the Medic accumulates Ubercharge. Once Ubercharge is filled up, Medic and his healing target can go invulnerable for ten seconds while the Ubercharge depletes, allowing stalemate-breaking rushes through the defensive lines. The game also recognizes assists when displaying the kills, and with the new tools and proper credit for supporting the offense, Medic is finally a fun class to play.

The operation was a success - the patient died.

Time to go nuts as the Ubercharge invulnerability lasts only ten seconds.

Just like in the original Team Fortress, the Engineer still the cornerstone of any defense, denying access to areas covered by his upgradeable sentry gun and providing ammo and healing from a strategically placed dispenser. The Engineer also plays a crucial role in assaults with the addition of teleporters. When used properly, they greatly shorten the time it takes for the team members to run back into the fight from the respawn point, and they can make or break a tight round, when the opposition is holed in to defend the final control point. Engineers could easily be grossly overpowered, and in the name of balance they are limited to just a single sentry, single dispenser and a pair of teleporters (entry and exit). While this may seem like a problem at first, in practice tending to just one set of toys is a full-time job, especially as the Engineer is armed only with a short-range shotgun and a monkey wrench, and enemies have the tendency to break all the toys and the Engineer when they run across one.

The Engineer and his toys.

Keeping the turrets repaired in the front lines can be hazardous at times.

A disguised Spy appears as a Spy wearing a silly mask to friendlies, while the enemies see something completely different.

The Spy is the master of mischief and surprise backstabs with the ability to disguise as a member of the enemy team. The Spy can also go completely invisible for a limited time - most useful for running through the front lines so they can turn up disguised in the rear, blow up Engineer toys, backstab people for some juicy one-shot kills and generate paranoia in the ranks of the other team. As Team Fortress 2 is designed to be played with friendly fire off, the best way to spot spies used to be "shoot every friendly, just to be sure". Early in the beta spies were too easy to spot - if a friendly guy bled when shot, he was a Spy. To balance things out, when disguised, a Spy no longer shows any blood, so the only sure way to know if someone is a Spy is to apply enough damage to kill him. As Spy loses his disguise as soon as he attacks, any team mate who is unusually restrained with his gun is also a suspect worth blasting away - just to be sure.

The best spies try to truly blend in with the opposing team and go for the "Master of Disguise" achievement by tricking an enemy Medic into healing them - so if you see "friendlies" in full health loitering around, yelling for Medic, you might want to blast them as well. In fact, the funniest thing about the Spy is how he can sow so much distrust into the opposing team that they keep wasting time and ammo while taking shots at each other. Divide et impera, indeed...