Arrival Radar: A Simplified Air Traffic Control Simulation Game

Your objective is to land planes as quickly as possible while maintaining separation between them

This constraint makes for some challenge, because planes arrive randomly and tend to end up violating separation minima unless you assign routes cleverly and actively

In order to prevent conflicts, you'll have to be deft at re-assigning routes and asking planes to join their route

That's all you can do, in contrast to other atc simulators which let you vector planes directly, assign altitudes and speeds, etc.