Star Tracker — free browser game

Star Tracker is a real-time version of the classic "which cup is the ball under" game: a star lights up green at the start and is marked as the target; 1.6 seconds later its light goes out and all the stars on the scene begin moving freely at an identical brightness. Your task is to track exactly this star with the mouse (with your finger on mobile) for 15 seconds. As long as your cursor is within 26 pixels of the star, the Accuracy percentage in the HUD rises; when the time is up, you advance a level if you were on the target for at least 70% of your total active time. With each level the number of stars increases by 1 (from 3 up to 14) and their speed rises; the stars also don't travel in straight lines — their paths constantly curve slowly, so even a brief glance away makes it hard to tell which one is your target after two stars cross each other. If your cursor leaves the screen the percentage freezes and resumes when it re-enters. The R key resets everything; Space / Enter are equivalent to the start and next-level buttons on the overlays. Tip: especially on crowded scenes, don't fix your eyes on a single point; remembering the empty space around your target star as a pattern (how far it is from which neighbour) lets you make the "which one was my target" decision instantly when two stars collide and cross — that is, track by the trajectory, not by the eye.