I would look forward to having dragons and other big creatures in this game and instead of slaying them you have to tame them and then you get lots of currants if you successfully tame them.
taming could be another skill to learn.
also maybe lots of creatures that you tame can take you somewhere, like a dragon can maybe take you somewhere high up in the air (only if you have a saddle and stuff like that)
or a sea serpent could take you to somewhere underwater (only if you have an air bubble).
also it would be cool if there are special houses in those special areas like a seaweed dome (underwater) and like there could be lots of bubble trees and seaweed trees underwater and maybe lots of gas trees in the air...