There are several portals on the planet, next to which there are certainly guards to prevent dangerous evil creatures and demons from entering our world. Since this is a big secret, a very limited number of people know about them, and the honor of becoming the guardian of the portal is inherited. You are one of the guards who holds the portal at gunpoint. For many centuries it did not cause concern, but suddenly a rupture occurred and dark entities poured out of it. You must destroy them as soon as the entity appears in your sight. It will turn red and you click to fire the shot. The number of monsters increases in Right Time.