This release marks the completion of the 0.6.x roadmap. Next up we'll be working through the items on the 0.7.x roadmap. For this release the major features are a new auto-evo algorithm based on miches that should generate much better AI species, and there's now a convolution surface algorithm which gives macroscopic creatures a "skin" in the prototypes. There's also a lot of smaller new features and tweaks to the microbe stage as usual. The last roadmap items to be completed where engulfing balancing and fixing as well as allowing continuing as a related species in easy mode.
You can read more in the devblog
Sorry, I meant that the organism stage is very early in development. However, you can become multicellular by using the binding agent, but they are still working on that part as well.