From Wikipedia: The main gameplay focus of Away is its "shuffle dungeons", where both DS screens show a part of the dungeon for the player to explore in. When a player enters a dungeon, they are given a few seconds to move Sword around both screens before a part of the dungeon starts to shift and reveal a different area for the player to battle monsters and open treasure chests. If a player dwells too much time in one of the dungeon's areas, they'll get caught in the shuffle and will lose a portion of their HP and start over in the dungeon before the previous one where you got shifted. After reaching the final floor of a dungeon, you'll either face a boss or collect gold or items from treasure chests and access a save point. Once you exit through the way you came from the dungeon, you'll be able to use that dungeon again to raise your stats and open chests.