Boat, climb, interact and explore in the beautiful ruins of a sunken world.
Players take control of either Miku or her brother Taku as they freely explore the flooded, open-world city. The game gives a sense of freedom, allowing players to boat across the tranquil waters and climb partially submerged ruins at their own pace, with no time limits or combat to worry about.
Traversing the open waters by boat is a key part of the exploration. Players can boat across calm seas and through storm-driven waves, with realistic water physics and weather effects that enhance the sense of immersion. When approaching points of interest, players can use their boat's telescope to spot collectibles and other items to investigate further. On land, the traversal switches to acrobatic climbing and platforming, which is largely automated - players simply move their character forward and they will automatically maneuver across gaps and up structures, allowing the focus to remain on exploring the environment rather than mastering complex controls.
Scattered throughout the world are light puzzle elements, including mechanisms like switches, levers, and bridges that players must interact with to progress. The puzzles are generally simple and straightforward, complementing the relaxed gameplay rather than providing major challenges. Solving these puzzles rewards players with access to new areas to investigate further.
As players explore the sunken city, they can collect a variety of items, including boat parts, outfits, and relics from the past. These collectibles not only help flesh out the backstory and world, but also allow players to customize the appearance of their character and boat. Progression is largely focused on finding the "seeds" needed to restore the corrupted plant life, which in turn unlocks new story content and areas to explore.