The game performs similar to a 2D platformer; you have to get from various islands, get objects, and not die, but there's a day/night cycle (each lasts 12 minutes and has it's own monsters), there are 100 monsters, and you must build a town/house/whatever.
When travelling by boat, it shows a top-down view of the islands. Islands that have towns have two or more houses on them, depending on their size. Tribe islands have ti-pis on them. Secret Islands have single houses or ti-pis on them.