Survive the night fighting off zombies from your barricade. Survive longer than a day by making use of the daylight hours effectively by repairing your barricade, searching for weapons and looking for other survivors to help repair and defend.
It's a nightmare. You are trapped in an abandoned mine with an injured comrade at your side against God-knows-what. Make your stand, get out alive. Three words of advice: shoot to kill. These things are not human, they are monsters..