I’d like to announce a new science-simulation game written in Java with the help of Processing, here it is:
Space Time Quest: http://www.gwoptics.org/processing/space_time_quest/
(Application for download for Mac, Win and Linux, GPL source coming soon.)
If you don’t want to download, you can also watch the tutorial: http://www.youtube.com/watch?v=lAvJrePR7F4
The game simulates the design process for building a gravitational wave detector. It is of course an educational game but we tried to make it fun to play, mostly by having nice graphics. The best bit might be that in the online high scores table you’ll meet the experts from the field. Try to beat those guys. 
As an educational game it might not be as much fun as a `real’ game yet. I would like to hear your comments on how the game could be improved to be more attractive to non-scientists.
I have been reading this forum for a while but this is probably my first constructive post. This game has been developed by myself together with some members of my research group. We have used Processing (http://www.processing.org/) as much as possible but the game engine has been written from scratch by one of my students (Daniel Brown). I have not seen Processing been mentioned much here, which might be due to the fact that it is aimed more at non-programmers. Anyway, I found it a very good tool to get programmers and non-programmers to work together on one project.
Andreas