Originally posted by The Killer:

lots and lots of tiny little islands all covered in thick fog

Is it a world seed from before the update or after? Either way, even old worlds will have continental mistlands regions. I ran into a fragmented coastline first too (I think many do), and it was devastatingly difficulty without taking things very slowly and with Biomass power right at the dungeon entrance. The cape helps a lot too, but it's not strictly necessary for enjoying the course.