Cunning Stunts
When the difficulty level goes up a notch, you've often got your troops by your side to help you battle through. The AI of your troops is superb and not only do they come in handy for distracting the enemy so you can sneak around the side and flank them, but they really do work with you, pushing forward when you push forward, moving up the battlefield in unison, jumping into the gunner seat of a Warthog or accurately firing at aircraft and enemies on foot.The enemy are also extremely cunning and react intelligently to your strategies, hanging back and finding cover if you reach for the sniper rifle or steaming in like a swarm of bees if you foolishly dive into the action too quickly. When you die and respawn you'll probably adapt your tactics, but you'll see how the enemy behave differently and change the way they attack you. The result of this enhanced AI means that Halo 3 is a joy to play; there's nothing worse than stupid AI and considering the amount of enemies you'll encounter, Bungie has done a stirling job across the board in creating AI that changes its behaviour based on what is happening around them.
It's difficult to find many negatives in the Halo 3 campaign experience, but there are a number of things that, for me, prevent the single player experience of Halo 3 from being perfect. I couldn't help, in some of the interior levels, becoming quite bored with having the Flood attack me at such a ridiculous rate and in such huge quantities. The Covenant spaceship is infested with Flood - so much so that you hardly have a chance to move one step without something leaping on you. I repeated this particular segment probably a dozen times and became frustrated at the sheer quantity of enemy. It wasn't skill that I needed, it was pure persistence, plus the ability to run and jump as quick as possible to the exit that got me through it eventually.