Slime Rancher v0.3.0, aka The Indigo Quarry Update is still in development, but you can check out a nice preview of the content on the official Monomi Park blog:
http://blog.monomipark.com/post/141269919002/were-happy-to-present-a-preview-of-our-upcoming
Thank you all for your patience as we develop this exciting update. We can't wait for you to begin exploring what we're creating!