Just published a puzzle game called "Puyo Puyo". The project is hosted using google's project hosting service and written in java. The license is LGPL.Currently it has a simple project homepage at http://limingchina.googlepages.com/puyopuyo.
If you have NetBeans 5.5 installed, you can check out all the files under /trunk/puyo and directly open it using the IDE. Of course if you are familiar with Java SDK, it should be easy to only check out the essential source code and compile and run it using the command line tools provided by the SDK.
The look and feel is rather primitive at the moment. But it could be improved over time. If you have interest, you can also drop me a line and we can do it together.
The first release (version 0.1) can be downloaded here. If you already have java run time environment installed on your machine, simply double click the jar file starts the game.
Have fun with it!