And the lord said "Let there be Halo 2" and it was granted.
The story is just as good as the first one, you once again play as the super soldier known as the "Master Chief " only that this time instead of killing the alien race known as "the Covenant" in the setting of Halo, You defend Earth itself from the invading alien race. However, your soon taken away from the defending Earth scenario and the game takes an odd twist as you are now able to play from the Covenant perspective. Though it seems strange at first this is actually a good thing because now you are able to know how the Covenant view the war and this actually adds more story to the game(sorry to disagree with you Greg).
The graphics are probably the only disappointing aspect of the game. While the game looks great while you play it, the cut scenes when they start,look really ugly and you see that the graphics switch from low-res to high-res when they start or go to another scene. Still the game makes up for its graphical flaws with great sound affects that make Halo 2 one of the best sounding games out there.
Game play wise, Halo 2 plays unlike any first-person shooter out there. The enemy AI in this game is amazing, your enemies will run for cover and try to flank you if your pinned down,and even on the easiest difficulty setting the games AI is still very good. Some guns can now be dual-wielded for greater fire power and this feature is very useful, but at the same time you can't throw your grenades which everyone who played the first Halo know that there very useful.
Overall, Halo 2 is thankfully the must have game that everyone was hoping for (like you said Greg) and anyone who is a fan of first-person shooters in general should not miss out on this truly outstanding game.