Halo 2 is brilliant. You've probably guessed that already. But it's incredibly hard to talk about in any depth for fear of spoiling it. It's a game you have to experience for yourself.
Bungie have seemingly done the impossible in keeping the single-player game under wraps for the totality of its gestation and there's a reason for this. It's full of twists - and one enormous one in particular.
Aside from the actual gameplay, Halo 2 is concerned with telling you an epic sci-fi story, and half the joy of the single-player game is derived from the narrative it spins.
So, before we go on - that twist. While we wholeheartedly approve of it, more could have been done with it. You'll know what we mean when you come to it and that's all we'll say.
Our other main criticisms are that there are perhaps too many corridors and interiors as opposed to wide-open spaces, and some textures construct themselves in front of your eyes.
Also, when the cooperative mode operates via vertical split-screen when in widescreen, leading to some annoying loss of peripheral vision. For a horizontal split-screen, you'll have to go back to the dashboard and change to the 'normal' aspect ratio.
There are other niggles, sure, but these pale into insignificance when faced with the greatness of the game as a whole.
The opening level might initially seem like a retread of the first game's intro onboard the Pillar of Autumn, but it ends with an epic piece of sci-fi grandeur that leads immediately into a battle on earth that very nearly threatens to overshadow the rest of the game.
Of the new additions, the Dual Wielding is a masterstroke that necessitates new gun-strategy and weapon-choice with every step. Weapon stratagems are also significantly affected by a raft of new firearms, both Human and Covenant, and the considerably expanded extra-terrestrial ranks.
While the single-player Campaign will occupy your initial love affair with the game, the multiplayer aspect will consume you for months to come, at the very least. If you've got Xbox Live you'll be astonished.
Despite all of this, Halo 2 is not a revolution. It is, however, the game we all wanted to see: a rich single-player experience, offering a beautifully presented future war, buttressed by mind-bogglingly comprehensive and well-supported multiplayer thrills.
It's not without its faults, but there's no doubt in our minds that there's no finer game on Xbox. Buy it and be amazed.