Lighthouse — free browser game

A lighthouse stands at the center of the screen, ringed by a rocky reef, surrounded by dark sea. Ships drift in from the edge of the dark sea, heading straight for the reef; each one carries a tiny wake-up gauge on its bow. Keep the beam on a ship long enough and the gauge fills, the captain sees the danger and turns 90° to escape the rocks — once a warned ship reaches the screen edge again, +1 point. A ship you do not light up shatters the instant it enters the reef ring, costing a life. Three lives and the run ends. The beam is a narrow 24° cone; hold the mouse pointer where you want it and the cone eases toward that bearing — or rotate it manually with ←/→ (A/D). Yellow speedboats arrive quickly and demand a shorter exposure, slower blue fog-flag ships warn a nearby vessel by radio once you light them, and black ships are 'deaf' — you must hold the beam on them for twice as long. Multiple ships approach from different bearings, fog rolls in (cutting visibility), and when your energy meter fills you can hit Space to sound the foghorn, briefly alerting every unwarned ship on the screen. Strategy: light the deaf black ship first (not the closest one) and brush the speedboat last with a tight sweep right before the reef. Best score is saved.