There can be little doubt that Half-Life was always going to be a hard act to follow but remarkably, HL2 manages to deliver much of what it promised.
A graphically superb game that amazingly will not have your machine chugging away, which is of course what we should expect from all our games - not simply something that demands the biggest proccessor and most expensive.
The play of the game is in itself fairly linear, you're generally quite well directed and so don't have to worry about pointless wandering. That said, even on the highest difficulty, this game won't challenge any experienced gamers and toward the end levels get a bit boring... although never quite slumping to the Xen level of badness.
There are some lovely set pieces in the game and the realistic physics are very impressive when you first play with them and of course the infamous gravity gun is probably the most innovative feature in an FPS for quite some time. You'll also get to control small teams of rebels and command antlions, not to mention driving around in a skimmer and a dune buggy.
More hints about the underlying events of the game are dropped too - although as one might expect, by the end more questions have been raised than answered... which is part of the appeal.
Ultimately, this game delivers but it isn't the second coming. The last few levels of running through the city fighting Striders are a bit samey and the Citadel is a bit of a joke - returning us to the days of jumping puzzles. The weapons are also a bit disappointing, the ammo limits are all a trifle low and the SMG has been horribly nerfed in terms of damage and accuracy but these issues can be easily forgotten when you immerse yourself in the atmosphere of this tour d'force.