Let me begin by giving you a big fat warning: this review contains spoilers. I'm sorry, but since the amazing revelations about what happens during DX2 start five minutes into the game, it's simply impossible to talk about it in any meaningful way without giving away at least a few of the secrets.

However, I can reassure you by saying that DX2 has so many secrets and twists that even if I listed out half a dozen of them right now there'd still be plenty more to discover. In fact, in some ways this is what's wrong with the game - DX2 is, like its predecessor, a conspiracy nut's wet dream with guns, but unlike DX1 it packs a similar number of shocking denouements into a game a little less than half the size.

Invisible War is not a long game. It's in keeping with most of what you'll see on the shelves these days - if you play in normal mode you'll have the whole thing bowled over in a little less than ten hours. So don't expect what the original gave us - an RPG-length romp in FPS form.

Here's the cute metaphor - if Deus Ex was the gaming equivalent of the Lord of the Rings book, then Invisible War is the equivalent of the blockbuster Hollywood trilogy films of the book. It's more spectacular, potentially more engaging, has brighter colours but is considerably more brief and doesn't give you that massive sense of achievement that finally ploughing through the original gave.

And yet this is not necessarily a wholly negative thing. Here's another cute metaphor - the hardest thing for a newly forged soccer team to learn is to pass BACKWARDS to their own defensive line. Ion Storm has learnt from DX1 that everything they included in the game was not necessarily good, even though it worked.

The classic example is lockpicks and multitools. It's easy to see that these are essentially the same device - and what's the deal with a tool that can hack electronically into a variety of devices but can't open locks? Therefore, lockpicks and multitools have been combined in DX2.

Something more contentious is ammo. In the new game, there is only one type of ammo, for guns as varied as the mag rail and the flamethrower. A quick bit of sci-fi gibberish about nano particles self-assembling the required ammo explains the unified system, but the gameplay rationale is to gie players access to their full arsenal of weapons all the time.

Different weapons use different amounts of ammo, as do different weapon modes. This takes some getting used to but ultimately makes the game more streamlined - you don't have to spend hours running around levels just looking for ammo.