Check out JavaFX Asteroids (using a thin Greenfoot emulation library in SnapCode):
JavaFX Asteroids with Greenfoot and SnapCode
http://reportmill.wordpress.com/2014/04/21/javafx-asteroids-with-greenfoot-and-snapcode/
I haven't done any performance work yet, but it runs well with a screen full of
asteroids on a MacBook Pro.
jeff
