Hold the Door

And of course those zombies are hungry for biting! But the world can still be saved, because you can hold them! And more specifically it would be enough if you could just hold the door. With your fingers.
So, the controls are easy, and of course the game is easy to learn, but hard to master.
Now go on and save the world from the zombies. Ah, just a pinch of salt - there are exploding zombies, too.