Use the WASD or arrow keys to move. As you move, you become more tired, as indicated by a rising yellow bar on the right. Once the bar turns orange, you are too tired to run. Your tiredness level recovers when you stand still, but, as you keep moving, the bottom of the yellow bar will slowly turn white. This is your level of exhaustion. It does not recover, and your tiredness does not recover beyond it.
If the vampire catches you, he begins attacking you. Each attack adds to your tiredness as you struggle. When your tiredness reaches the maximum, he overpowers and kills you.
If you manage to hide from the vampire, he will methodically search the house for you until he spots you again.
You can push tables, chairs, beds, flower pots and chests of drawers by walking into them. After a moment, they will shift by a tile. You can use them to block off doors and impede the vampire's progress.
Chests of drawers may contain useful items. Stand next to one and hold down E to search. Once searching is complete, the chest icon will change to show holes where the drawers were and you are told whether you found anything.
There are three items in the game you can find: the keys, the gun and the leather jacket. They are indicated in the top right of the screen.
The key allows you to lock and unlock doors, impeding the vampire's progress. The vampire can and will break down the doors, but it takes him a while. Press space when next to a door to lock or unlock it.
The gun lets you shoot the vampire, slowing him down. Use the cursor to aim. A line of speckles will appear showing the path the bullet will take. Click to fire. While the vampire is injured, he has a red splotch on his body, moves more slowly, and takes longer to overpower you.
The leather jacket lets you resist the vampire's attacks for a while, but it will eventually be in tatters and discarded.
Once dawn arrives, the vampire, too distracted by the chase to notice the time, will be incinerated instantly by the sunlight.
If you win, the next level requires you to survive for twice as long. Enjoy!