Space Invaders Enterprise Edition is a version of Coke and Code's Space Invaders implementation, but all the game logic is represented as a Drools rule file, rather than written in Java.
This code is released under a BSD license (as was the original code from Kevin! Open-source is awesome!), so you can do with it as you wish, I just take no responsibility for your crimes :)
You can build this by using Maven: mvn compile
and run it using Maven too: mvn exec:java
Packaging is a little hard right now due to the timer.jar library. I haven't worked out how to get Maven to bundle that up with the assembly plugin, so mvn package isn't going to produce a JAR with dependencies that will actually execute.