Aside from his standard attack and ability to eat the brains of his foes, Stubbs has four special moves which are activated whenever you eat enough brains. These are the 'Evil Hand', which allows you to take control of any foe not wearing a helmet, the 'Gut Buster' which lets you throw what is effectively a grenade at your enemies, the 'Head Bowling' attack which lets you clear out a bunch of enemies in much the same way the grenade does, and 'Zombie Flatulence' which stuns any opponents nearby. Be sure to use these special moves when they're available, since while you can have three 'Gut Busters' stored up, you can only hold one of the other move types at any one time. Remember that if you do take damage, you can back off and you'll heal automatically as long as you don't take any damage while you're resting.
Anyone you kill as a zombie, whether it be by eating their brains, clawing them to death, or blowing them up with Gut Busters will result in them rising from the dead as zombies. People killed by vehicles or by human characters under your control will not rise from the dead. These zombies will then follow you - typically you can have ten following you at any one time as any others you convert won't follow you for some reason. The zombies will attack any human characters, converting them to their cause or dying (again) in the attempt.
There are essentially five groups of enemies you'll encounter. These are:
Civilians: Easy fodder for you or your zombies, a few civilians will fight you but they won't do much damage and they can all be taken down with a simple bite to the head, achieved by pressing the 'Y' button.
Cops: The cops are bit harder to deal with since they carry pistols and have to be stunned before you can eat their brains or kill them. Whack them a few times using your basic attack (the 'X' button) and they can be killed or brain-munched. The notable exceptions are the Riot Cops, who have helmets and can't have their brains and are also harder to beat. The best way way to deal with them is to get behind them and pull one of their arms off, which can then be used to beat down their fellow police officers.
Punchbowl Militia: These gun-toting rednecks pack a little more punch than the cops, toting shotguns and muskets, but they can still be dispatched in the normal matter. The one exception are the chainsaw-wielding milita who are best dealt with by ducking beneath their swipes and hitting them back.
Soldiers: The soldiers are heavily armed and should ideally not be faced head on in numbers. Instead, you're best off using your evil hand skill to take over one - one who isn't wearing a helmet - and using him to gun down the rest. Some soldiers drive tanks and the only way to deal with them is by using your gut grenade or head attack to blast the tank.
Punchbowl Security: These singing barbers are fairly tough, but not too heavily armed. You can dispatch the ones on foot without too much hassle. The problem is when you encounter the ones equipped with jetpacks who dodge like crazy. The best way to finish them off is to throw a gut buster at them and explode it manually next to them or to use your hand to possess them and then use them to annihilate their comrades:
Welcome to Punchbowl/Breeding Ground: These two levels are fairly easy, containing only cops and civilians. The Breeding Ground levels mark the introduction of vehicles, the Sod-O-Mobile, which is essentially a hovertank. The best tactic here is to jump into the tank, use it to take out the enemy in their Sod-O-Mobiles and then get out and head along on foot. Granted, you could use the Sod-O-Mobile to obliterate all your foes, but it's much more fun to shamble along, gathering a zombie army.
The Slammer: There are more cops here, and since your operating in close quarters, there's not much room to maneuver. Your best tactic is to sneak around the pillars you encounter and get behind the cops before chewing on their brains. Halfway through the level you'll be captured and have to use your hand to take over a cop by sending it down an air vent. Unless you want a real fight on your hands, keep your weapon holstered - note that you can only ever use weapons if you're controlling a human - until you've freed yourself by hitting the 'release' switch near the lab.
Cop Rock: A simple-simon style game section, you have to remember the colours and hit them in the correct order to progress. You can skip this section by pressing X when prompted, but if you do want to play it, you can hit the right moves before they flash and still have them accepted.
Painting the town red/Punchbowl Maul: This is a walk through Punchbowl's commercial district, culminating in a battle against a chainsaw wielding redneck. Remember to use the multiple levels of the mall and parking garage. If you're getting annihilated by the rednecks outside the mall, try using your hand to scramble up to the platform above the entrance, take over a redneck sniper and use them to do your dirty work for you. As for the chainsaw wielding boss, duck under his swipes, get in a few good slashes and then back off and heal. Take his arm off when you can and repeat in order to defeat him.
Fall of the House of Otis: Use the cornfields to your advantage, by jumping out to maul the rednecks, then jumping back in before you can be shot. You'll encounter a tractor halfway through this level, so jump on it and use it to take out the chainsaw wielding rednecks who'd otherwise give you problems close-up. The major problem you'll likely to run into are the machine gun nests - a few bullets from these emplacements can take you down in a matter of seconds, so use your hand to possess the machine-gunner and use the emplacements to gun down the other rednecks.
When the Zombie Breaks: More slaughter, this time at a dam. There are no massive threats here, though the end of level bit is interesting. You have to relieve yourself into the damn to contaminate the water supply, but the enemies are trying to stop you. Don't let them overrun you - instead, keep stopping to deal with them individually, turning them into the living dead, and then carry on filling the damn up.
The Sacking of Punchbowl/Paved with Good Intentions: These two levels have you pitched against the soldiers, who are really capable of kicking your backside, so use the zombie hand whenever possible to use them against their friends, and throw in a few gut busters for good measure. You'll run into tanks a couple of times, so use the bowling ball head to roll under the tank and blow up the driver, then get into the tank yourself and cause some damage.
The Doctor will See you Now: Taking place between the above two levels, this sees you taking on the mad scientist responsible for having you captured earlier. His comrades won't cause you any problems but he's a different kettle of fish. You have to hit the pads into his control room to turn off his shield, and then use the gut grenades near to him to finish him off.
Ghoul of your Dreams: This is it. After fighting your way up to the office of the creator of the city, Andrew Monday, you get to take on the man himself. You have to attack his shields till they disintegrate, then throw a grenade at the man himself. Trouble is, you're constantly being assaulted by his guards and civilians with wrenches. The way to deal with them is to duck into one of the side rooms around the complex, then chow down on a civilian till you've got a zombie hand power-up. Use your hand to take over one of the barber security guards and use him to zap the shields. Rinse and repeat and you'll finish off Monday and see the oh-so-lovely ending in no time at all.
It is well worth playing Stubbs the Zombie again a couple of times, since there are hidden 'hippo' icons to be discovered which give you access to a director's commentary on the game. Plus there's the co-operative mode itself which is fun. Shame there's no deathmatch mode or sandbox mode, but maybe that's something for the sequel.