Air Traffic — free browser game

You are an air traffic controller. New planes keep appearing from the edges of the radar screen; each plane has a colour and must land at the runway gate of the same colour (the rings at the edge of the screen). You tap a plane and drag your finger (or hold the mouse down and drag) to draw the route it will follow: the plane follows the path you draw, and when the path runs out it keeps flying straight in its last direction. A plane that reaches the gate of the correct colour lands and your score goes up by one. You can change a plane's direction at any time by drawing a new route. The one rule: no two planes may ever touch — the moment a collision happens the game ends. As your score rises, planes arrive more often, so plan routes ahead of time so they won't overlap; think of separating the planes onto different paths rather than different altitudes. Passing over the wrong gate is harmless — the plane doesn't land, it just flies over it; a plane that flies off the screen quietly disappears (no points lost, but an opportunity missed). Your high score is saved in your browser. To start, or to restart after a collision, just tap the screen; the R key or the 'Restart' button also resets the round.