Protect the cargo

Earth has been taken over by a viral zombie infection. The world has descended into chaos. A company you work for has developed a drug that can temporarily prevent people dying from the infection and becoming zombies. This could be a game changer. You need to transport the drugs across town to a military base. But your truck crashes so you need to protect it until reinforcements can arrive and help you. There is a turret sequence where you must protect the base using a high tech military turret....