You are a volcano. You have come a long way from the ocean floor, erupting and building up new rock slowly throughout eons. Eventually, the top of you emerged from beneath the water and your lava began to form an island around you. Some plants and animals arrived over time, whether under their own power or brought to you by the wind and the waves, and you enjoyed watching them spread across your surfaces and flourish. All the while you continued to erupt, slowly building your island.
Recently, a violent storm blew several boatloads of creatures towards you, and you held your lava in, trying not to hurt them as they crashed on your shores. When they emerged from the wreckage of their crafts, they started building structures on you and establishing a new society. You relaxed and allowed your lava to flow again, but it didn’t flow as freely. You feel that there is pressure building up inside of you that might someday cause a massive eruption, and now you are trying to find a way to release this excess pressure before it dooms the inhabitants of your island.
Source: The Developer Website.