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Explore a quiet island, take the boat beyond the shore, and investigate the remains of a story left around the coast. Your chart fills in as you travel. Compare what you find in the journal, use landmarks to get your bearings, and search above and below the water. The treasure is something to work out, with room to wander before the pieces connect.
Desktop keyboard and mouse, a WebGPU-compatible browser and supported graphics hardware. WebGPU must be available; there is no WebGL fallback.
Explore the starting shore and read what you find before setting out. Use the chart and journal to compare places and evidence. At night, press F for the flashlight. Look below the surface as well as along the coastline.
Exploration, discovered evidence, chart notes, puzzle progress and your player and boat checkpoint are saved. Sign in before playing to continue with your account on another supported device. Guest and account saves are separate.
Castaway Island is built around observation and connections. Give yourself time to learn the shore before expecting every object or distant landmark to make sense.
Walk the starting shore and press E when there is something to examine. Open the chart with M to see how your exploration has filled it in. The journal, opened with J, keeps the evidence you have discovered so you can compare it without relying on memory.
A view from a different height or direction can change how two landmarks line up. Use chart notes and bearings to keep track of a promising idea, then check it against what you can actually see. You do not need to solve every clue the moment you find it.
Use E at the boat and helm to get underway. WASD controls movement; V changes the boat camera. Before leaving, look back at the shore and pick out a recognizable landmark so you have a reference for the return trip.
Travel opens up more of the chart. Look for places worth approaching, explore on foot when you arrive, and return to earlier evidence after you have seen the island from the water. A new location can give an old note a clearer meaning.
Swimming is part of exploration. Use Space to rise and C to dive, and pay attention to the shape of the coast under the water as well as on land. Revisit a promising stretch from another angle before dismissing it.
At night, press F for the flashlight. The scope lets you inspect a distant view; use the mouse wheel to zoom and Q to leave it. These are tools for observing the environment, not shortcuts that reveal the complete route to the treasure.
Your explored chart, discovered evidence, notes, puzzle progress and player and boat checkpoint are saved. Before taking a break, look at the journal and chart so you know which connection you want to investigate next. Guest saves and signed-in account saves are separate.
Click into the game to capture the mouse; Escape releases it and pauses. H opens settings and N toggles sound. Castaway Island requires WebGPU and supported graphics hardware; it cannot fall back to WebGL if the browser does not provide WebGPU.