After a few requests I decided to create a little java library for how to create a 2D game in jME.
This library will assist the user in making a 2D game with or without physics.
I make use of Dyn4j as physics engine.
Please give it a try and let me know if there is any difficulty using it.
I do have a good wiki page of how one would use it under the readme file.
Never mind, I see what happen and I also fix it. Just use jmonkeyEngine sdk to create a Java Class Library and import all the Galago2D source code in it , and also import .jar file that galago need. Then just simple build to jar, and import to another project libraries.