I've been playing Worldle for a while, and noticed that colder countries seem to have more rugged coasts. See Svalbard for example:
Whereas e.g. Bali is smoother:
Does it have something to do with the ocean being stronger in colder climates and washing away more of the "softer" parts of the coast over time? That's just a layman's guess, I'm really not sure.
Excited to learn about this if anyone knows the answer!