Zombie Driver keeps the story fairly simple and traditional of zombie games. The city is overrun with zombies and the army won't let you leave the city since they have it under quarantine. You end up helping to maintain the infection and rescue any survivors. The game is comprised of 3 modes; Story, Blood Race, and Slaughter.
The common game-play elements in each mode is that you drive around in a vehicle and use a combination of ramming as well as weapons to eradicate zombies. The view is isometric but almost top down, so is reminiscent of the early Grand Theft Auto games; especially when you are running over humanoid figures. As you drive around, you will need to keep an eye out for pick-ups. You can only have one weapon equipped and each has limited ammunition, so you will be constantly grabbing anything you can find to help in your mission. In addition to the repair kit and nitrous, the weapons include rockets, rail gun, machine gun and flame-thrower. You can rack up larger scores and monetary bonuses by achieving combos when killing zombies and destroying the scenery. Bizarrely, parked cars seem to blow up with a minor touch, but it isn't the kind of game to be realistic, so the arcade touch can be overlooked.
There are a few different zombies that you'll encounter. There's standard zombies, ones that throw projectiles, large zombies, zombie dogs, and finally, the fat zombies which explode when in proximity, causing massive damage when hit. Running over the non-exploding zombies is easy to do, but hitting them will slow you down. You need to be careful you don't get caught in a group and become surrounded, although use of the nitrous speed boost will get you out of those situations. There's masses of zombies, which increase dramatically as you progress through the game. There are spawning objects on the map which is a good idea to focus on these first when you encounter them.
Each car has different attributes and therefore handles differently. Each car has armour, ramming capability, and speed ratings, all of which can be upgraded as you acquire money throughout the game. You may choose your car based on the mission objective, so if you are going for a time-limit, you may prefer speed, but otherwise you may be more inclined to go for the armour or ramming ability. Since most story mode missions involve picking up survivors, there's going to be a large weighting for the higher capacity vehicles like the limo or the bus. This will save you making several trips back to base to offload the survivors.
In Story mode, some missions in the campaign gives you the choice of cars while others have a set vehicle. You are usually given a set objective of clearing out certain areas of the map within a time-limit in order to pick up the survivors in the near-by buildings, and then drive them back to base. There are some destruction based missions such as the ones involving taking down the spawning areas, or ones involving boss battles. Secondary missions are usually optional targets or even a time-limit to complete the entire mission. Completing these usually involves cash bonuses which can be put towards weapon or performance upgrades for your car. Missions are fairly short but there are 31 of them so collectively they will keep you busy for 4 or so hours.
In Blood Race, tournaments are comprised of numerous stages. There's a Race type, where the aim is to cross the finish line first. Along the way you can slow your opponents down by using weapons to blow them up. In Eliminator, you are given a target of destroying a certain number of cars as you race through check-points to extend your time. Endurance is a time-trial style race where passing through check-points or gunning down zombies gives you bonus time. Blood Race mode is full of intense action, since the AI is aggressive and is constantly attacking whilst driving at high speeds. Since you can't see that far ahead, you need to keep glancing at the map to anticipate the upcoming roads.
In Survivor, you need to survive waves of zombies in an arena. With each wave, new upgrades are awarded and appear on the map. The map can feel a bit cramped due to the small size and it's easy to resort in driving round in circles.
I think each game mode is just the right length to complete without the game becoming boring. You can revisit the modes to improve your scores and aim for the gold medals in the Blood Race and Survivor modes. The idea of game might not sound appealing or entertaining to a lot of gamers, but personally, I thoroughly enjoyed it and thought the game provided good fun and great value. The solid execution makes it a blast to play through from start to finish.