I converted the monkeyzone project to a gradle project and started using JME3.1.0-beta. you can clone it on github SkidRunner/MonkeyZone.
I left almost everything the same except replacing the logo with the new monkey and changing a bunch of stuff with nifty to use the new nifty controls I should go through and set all the labels widths to 100% to solve some issues you will see it you test it out.