Of all the hand-to-hand combat moves in the game, disarming a target may be the most effective. When fighting large groups, disarming can turn the tide in your favor, because none of the enemies in the game, except for the bosses, are any match for you in hand-to-hand combat.
The one drawback to disarming opponents is that if you can't pick up any more ammo of the type they were using, the guns will just sit on the ground until they get back up and grab them. So make sure that once you disarm opponents, you knock them away from their guns.
Kick 'Em When They're Down
Speaking of knocking them away from their guns, hand-to-hand combat will be much easier if you learn to execute a low kick after you've knocked someone down. You can kick your opponents around the screen like a soccer ball, and usually one or two of these kicks will incapacitate them before they can even get back up.
Your opponents will be universally terrified of friendly fire, so use this to your advantage. If you are fighting large groups of scattered enemies, if you get in close to one, the others will be pretty much unable to respond until you've hurt their friend. This is also a great way to know whether or not an enemy you're fighting is down for the count, which can sometimes be difficult to determine in the heat of battle. If his buddies start firing at you and he's still moving, you'll know he's just doing his death animation.
Get Your Bearings
Knowing where to go in Enter the Matrix is sometimes tricky, because the perspective can often obscure a path. This isn't always the case--most of the time the path through the game is obvious because you'll just be running down an endless series of corridors.
On the off chance that you do find yourself at a dead end, switch to first-person mode and look around. This will allow you to look down and up, which will sometimes reveal a path that you may have missed. Also pay close attention to your objective arrow, which is often extremely specific in showing you where to go, to the point of pointing out doors and otherwise hard-to-see paths. This last point is especially important in some of the driving missions, where the perspective can often obscure necessary turns and side roads.