You'll need to complete first episode and get your ID card to enable global travel. After that - just talk to the ferry to get your ticket. Travel by ferry is time consuming, route to Purple Island will take 6 hours of game time.
Right now, travel is free of charge, but we will change it as soon as we add some grindy job in the new area.
Not enough jumping power? Yes, but:
You will be able to increase that, we are working on level up system. Level 1 strength is right on the edge to jump over the blocks in Purple Island area. That's annoying, but that's annoying for reason - for character development to be valuable.
Save frequently
Purple Island is work in progress, you can and you will stuck.
Use more than one save, new objects might be placed on top of your saved position. Take care.