Hey, it's mostly a technical update, content-wise there have been only minor changes.
The biggest part is the update from Unity 4.6 to Unity 2017.4 (there was a Unity 5 beta but never actually released) as well as many asset optimizations to reduce the game size.
From the recently released mobile version of Feist we've also brought over touch support, so if you e.g. have a Windows tablet with multitouch input, you should now be able to play Feist with the new touch UI.
Overall, we hope the new version runs better and more stable and has improved compatibility with newer operating systems.