If you remember the Hunted President from Quake1 TF, you're in for a surprise when you try it out in Half-Life. The president's goal is to make it to his escape vehicle. The assassins are out to prevent that from happening. The bodyguards are there to, obviously, guard the president. Only problem is that the area containing the towers is a huge, open airfield.
Snipers can rack up the kills out here.
The classes remain true to their Quake1 originals, though it's great to see not only new skins, but slightly changed models. The visible weapons help, too. This really beefs up that class, but I think it also throws off the balance a little. The only other problem I can think of is that if you stare straight up and shoot a grenade, it ends up about fifteen feet behind you. If you're like me, and have been playing Team Fortress for years, you'll probably become burned out on Two Forts, Well6 and The Rock pretty quickly.