Well done! Yes, It's true, I regnonize David Brackeen's "framework" (ScreenManager, GameCore, etc)
However you made it much better!
If you're interested, I'm looking for motivated guys in order to create a Lemmings "exact" clone in Java (yes, one again). It would be called "Jemmings" and would feature fullscreen mode, improved music (new arrangements with high quality sound), and would also include "Hollydays" ("Christmas) levels and new ones. All this would be open source.
Again, congratulations for your JMario