My Pros and Cons on Half Life 2.
Half Life 2's graphics engine is cutting edge and will be superior for years to come, especially with its use of physics on objects in the game. Because of the physics, its the best action I've seen in a game, and you can use the environment against your foes. Shoot the leg out from a small bridge and have the whole thing fall down on some unsuspecting foe.
Game runs on just about any PC system and still displays tremendous graphics potential/runs at a good frame rate (game also on original Xbox game console for the TV).
Alot of "little touches" on the graphics. Its great to see the wind from an aircraft push up the water into a mist, see the little breaks in glass, and see how light reflects around each tile on a floor (thanks to mipmapping graphics).
Artificial Intelligence has more precision and enemies know their environment well and will spread themselves out among an environment in a smart display of their use of gun fire. You won't see an enemy be stupid and crouch down to think they can be tough enough to take the blast radius of a grenade like in the original game. They know how far to clear a grenade and will not let that stop them from "taking you out".
The environments have a great presentation. Its great to see how the series continues on. Its like being apart of some really good movie and it has more creativity than any movie can muster out. You just can't get this kind of detail from a movie, and when you are the one pulling the strings and doing what you want in it.
Story in the game is well thought out. You really want to care about the characters in the storyline. Even though the game doesn't have any real squad based combat (see one of the cons below), it feels great to fight along side your "brothers in arms" and protect their cause.
Cons =
Artificial Intelligence of enemies lack any real squad-based combat tactics (with the nature of my real life career, this would be a great amusement to me), but I guess this would make the game close to impossible to beat.
The missions based on vehicules are a bit too long, but help the game to not be too repetitious with run and gun gameplay.
Story is set-up similiar to the original where much is a mystery and you figure things out yourself (I had to look around my environment, like I looked at a newspaper posted up on a wall and it helped me find out how the world reacted to what happened in the original game with aliens invading earth), however because of the better scripted sequences with Non-Player Characters, the story and presentation is much better than the original.