Travel with your newly found raft through the ocean and get to The River, fighting against anyone and everything in your way. They keep coming so do not rest. Fight with increasingly harder vessels and environments, while improving your raft with the flotsam you find. If you thought being alone in the middle of the ocean was difficult, getting near The River is hellish. Don't quit, don't die, and you will hear the Roar of The River soon... Or later. If you can.
Work in progress. This is Gough Island (Tristan da Cunha/UK). It is part of the scenery of RUR. This shot is still in blender as we use it to check out the generated meshes.