AresEd is a Free and Open Source 3D Game Creation Toolkit for GNU/Linux and Windows. With AresEd it will be possible to create full 3D games using the Open Source Crystal Space 3D Engine (https://www.crystalspace3d.org) complete with game logic. Build your 3D models using tools like Blender, make your textures with tools like Gimp, and put everything together in AresEd. You can place objects and define game logic for them. The player will be able to interact realistically with the objects using physics (done with the Bullet physics library).
AresEd is still alpha software. It is not feature complete and there are many known and possibly unknown issues. So we are looking for developers to help us develop this potentially powerful tool. Contact us if you are interested.