I’m putting the finishing touches on another 4k game: Don’t Reach the Square.
http://groboclown.net/games/drts-4k.html
The game play is fairly straight forward: there some mines which are attracted to the center square, and repelled by your mouse pointer; you need to prevent them from reaching that center square. You can also create a “force ring” that pushes the mines away.
It has a (mutable) sound track, so you may want to adjust your speakers as necessary.
I’ve tested it on JRE 1.6.0 on both Windows and Linux.