Neptune Island is a short puzzle game where you have been tasked with repairing the light of a lighthouse. The light has been out for some time, and the owner hasn't done anything to fix it. Unbeknownst to you, you have a much more difficult job ahead of you than you anticipated...
After a long journey in your small rowboat, you arrive at Neptune Island, set on repairing the light atop the lighthouse. However, a series of puzzles designed to deter intruders stand in your way, each one growing more desperate as you get closer to restoring power to the light. With only a weak lantern to guide you through the darkness, you must navigate the lighthouse's challenges, and ensure the safety of sailors in the surrounding fog. Along the way, you'll uncover the strange phenomena that make Neptune Island unlike any other.