The zombies are endless and i think the shooting is fast.
Clicking the mouse to shoot zombies and aiming for headshots to score points is how you start playing, you have to use your skills to target the undead effectively in this game.
Inside the haunted house, you face waves of zombies that test your reflexes, which is kinda weird anyway, and you use your mouse to aim and shoot the undead, their main goal is to survive the levels and get points.
Quick tip, i found that aiming for headshots gives more points then just shooting randomly, you have to use your skills to target the zombies effectively, it is better to focus on the undead that are closest first.
Gameplay is simple, you click to shoot the zombie thingy and try to get headshots for points, you have to deal with the undead and use your aim skills, the whole thing is about surviving the waves in the haunted house.