Welcome to Tower, the airport traffic control simulator. Your task is simple. Guide aircraft of various sizes and capabilities to and from the active runway for departure and arrival. Direct them as to when it is safe to enter/cross runways, which taxiways they are to use, when to turn or go straight, stop and start, take off and hold short.
It should be easy, just look out the window. Of course, it may be dark, or foggy, or be raining so hard you can’t see the ground, to say nothing of those two heavies that are getting closer as we speak.
Sure, those guys and gals who direct the traffic once airborne have it easy. Plenty of sky in which to push the tin. You, on the other hand have only a limited amount of concrete and a bunch of street signs, along with lots of impatient pilots and passengers who don’t want to hear about your problems.
Enjoy Tower Simulator!