We all know Halo 3 is the second sequel to Bungie's hit game Halo: Combat Evolved. We also all know that we play the role of Spartan-117: Military Rank Master Chief, Earth's last hope against the Covenant onslaught.

So I might start with the improvements over the first two games. The first noticeable improvement is in the AI. The AI in Halo 3 is now more intelligent, and less artificial than the previous two offerings. The first time I picked up on the AI being improved was quite early on in the game: you get into a M12 LRV, or Warthog as we know it. After getting in the driver's seat, you make your way to an exit. As you are ready to get out and activate the door, one of your fellow Marines calls out, "I'll get the door for ya." In the previous games this was unheard of; your allies had all the pro-activeness of a surly teenager.

But the improved AI extends from your allies to your foes also. In Halo, and in Halo 2 for that matter, taking out squads of Grunts was easy; take out their leader, and they would run around in panic. Halo 3, however, sees a departure from this dynamic: a Grunt after seeing his leader fall is now likely to prime two plasma grenades and charge you. As the Brutes from Halo are now the main enemy, they take charge and will gruffly order the Grunts and Jackels about, and order them to flank you.

The weapon set has seen a substantial amount of improvement. All of our favourite guns from both games are back, and our not so favourites for that matter. And for the final game in the trilogy, Bungie have added a whole swag load more weapons, from both UNSC, and the Covenant forces. One thing that I always found somewhat bemusing in the previous games was that Master Chief, despite being super strong and wearing armour that enhances his strength even further, he wasn't able to wield gun turrets with out a tripod. It would now seem Bungie heard my mind chatter.

The downside of wielding the turrets is they only have a finite amount of ammo. If you do yank the turret off its legs, you can effectively carry three weapons plus your grenades. With regards to weapons, the auto target feature from the rocket launcher has been removed, giving the pilots of vehicles and turrets a bit of breathing space.

Grenades have been a staple weapon in the Halo franchise. In the previous games you had access to a total of eight max. (4 frag, and 4 plasma). Halo 3 still allows you to carry eight, but now there are two new types of grenade: the stick grenade, and the incendiary grenade, so you can only carry two of each. The stick grenade has a number of sharp prongs that stick to anything: enemies, walls, vehicles, and allies if you're an exceptionally bad thrower.

Quite probably the coolest addition to Halo 3 is the inclusion of new battle equipment. Battle equipment is items that can be dropped by either human or Covenant soldiers and come in the form of either offensive weapons, for example proximity mines. Or defensive such as the bubble shield as seen in one of the earlier adverts. But there's also a range of powerups included, such as active camouflage.

Due to the new battle equipment being added, Halo 3's button layout had to change a bit. For example, weapon pickup is no longer Y, but the right shoulder button. The left bumper handles dual wield, reload left weapon or cycling through your four types of grenade. X is now for the aforementioned Battle Equipment, so reload has moved to the right bumper. About 10 minutes into the game, all controller changes are forgotten, and you will be running and gunning with MC like a long lost friend.

The unfortunate reality of Halo 3 is that not everything is improved. You may have noticed that above in the improvements, I didn't mention the graphics. Sure there are more enemies, vehicles, blades of grass and leaves on screen at any one time. And as seems to be the way of Xbox 360 games of late, the water effects are great, (although I find it hard to believe a 7' tall, genetically enhanced super soldier wearing a ton and a half of armour could float downstream). But for what is (let's be honest) a second generation title for the Xbox 360, the frame rate is still short of 60Hz and there is quite a bit of aliasing in the game; the edges just don't look smooth. Not only that, but in the middle draw distance there is some fogging happening on quite a few in-game items. I would have thought this would now be a thing of the past. Gears of War, released nearly a year ago, looks better in my eyes.

Then there is the seemingly random difficulty level. I played through on Heroic; at the start of the game I found this difficulty to be relatively hard, but acceptable. A few levels in, though, and it was a different story: I had no difficulty at all - only for the game to be made difficult again in the ending couple of levels, by having a seemingly never-ending supply of foes.

Multiplayer, though, like Halo 3's predecessors, is where Halo 3 really, er, shines. As there are more game modes than you can shake a stick grenade at: Slayer (free for all), Team Slayer, CTF, Big Team Battle, Zombies (a custom variant made by gamers for Halo 2) and many more make a welcome return. There are ranked and unranked matches to enter, so you can have a fun social game or get competitive. As per Halo 2, you can set up custom games and only invite your friends, for that more social game.

Most of the game variants can be tweaked for your liking, but not enough in some cases. In one game I set up a match of team shotguns only, only to have the other team pick up gun turrets and shoot us from long range (kinda defeats the purpose of having an up close and personal gametype.) So after the match I had a look at the variants setting to turn off turrets, grenades, vehicles, etc, only to find you can't.

A way around this little glitch is the new Forge mode. Forge is a game type that allows the players to become a guilty spark type monitor (from the single player game) and move, or even remove spawn points, weapon placement, vehicles, and other 'scenery' to anywhere on the game map. The downside for the above shotguns example is there is nothing to stop a player from putting a sniper rifle in the map for him to pick up and move to high ground (except trust of course).

To help with customisation of your very own Master Chief, Bungie have given us a lot of armour models to choose from, and a healthy swag of unlockables. Also on the Multiplayer front, there is four player co-op, playable over Live, splitscreen or LAN.

Another new feature for Halo 3 is fileshare. If you pull off that amazing head shot, kill three players with one 'magic bullet' or get that plasma grenade stick from the other side of the map, you can now watch a replay of your feat, and save it for later, then share with all your friends, or upload on Bungie's website. There are quite a few amazing videos that have been posted that defy belief.

Does Master Chief die? For those that haven't read the books, do we learn Master Chief's name? Who are the Forerunners? Does earth get glassed? Is all Humanity lost? All these questions and more are answered in the game; it is a fitting end to the series.