Hi,
I have a project that you might be interested with.
I am a phd student working on robotics. In addition to my thesis studies, i am developing a Java-based robotics simulator (actually a simulator, a simulator gui, a framework to run experiments on grids) and i plan to transform it to the first robotic IDE with the help of Netbeans platform (may support Eclipse in the future too).
The simulator will be open source. It is a new project but the base code is already shaped and have a working version. The GUI part currently support point-mass simulation of the robots with a 2D view but i would love to and plan to have a physics-based implementation with a 3D view. Here 2D, 3D views and physics based models of robots are related to gaming. I dont have much free time to work on an independent game other than my simulators although i think that that area is interesting too.
The GUI also has a console and with the help of JSR223, it is possible to access/modify simulation objects at runtime. In the future, i plan robot behaviors to be programmed in any language too..

There will be XML support which will be used to read robot placements, initial speeds etc. (in this way, the users will not need recompile their codes to run it with different configurations.).
We have developed (and still developing) robots designed for swarm robotics specifically. My main research requires me to work with them at this stage and the first robot being supported by the simulator will be these robots.
Our lab also has a good simulator, written in C++, specifically for physics-based models with 3D view. But i love Java and i believe Java will open new doors in this area..
The project will be open source. You might be interested in improving the simulator to support 3D and physics-based models. But of course, this might not be the type of interaction you are looking for. I understand that if it is so. Let me know if you are interested to help/work with me to improve it. If you reply to this thread, i can contact you with PM with further details.
Thanks.