Radar Chaos
In-game instructions link is dead. Use https://bigfatsimulations.com/game/radarchaos instead. There's a video and an "Instructions" button at the bottom.
That's also where you can buy the full, paid version of this demo. The in-game "buy full version" button charges more and may not actually work.
Take control of the arrivals and departures from the control tower in this realistic radar-based air traffic control simulation game. You must control the altitude, speed, and path of all the planes in your airspace and make sure they all abide by the rules of separation: 3 miles laterally, or 1000 feet vertically.
Use the MOUSE and LEFT MOUSE BUTTON to interact with the planes. LEFT CLICK on a plane to select it, then LEFT CLICK on the various options that appear to alter its altitude, air speed, and heading.