I found this 3d game software the other day. It's
a game engine called Unity 3d. Looks like a nice
deal for the amateur game designer or even the
professional.
http://unity3d.com/unity/The software appears to be free for the pc/mac. You can
import from several 3d programs like Maya, 3dmax, and
Blender as well. Virtually drag and drop the files to the
engine software.
They sell various scene builds if you don't want
to make them yourself.
If you wish software to create games for mobile devices
they have a trial use period of 30 days for that.
Nothing like free software to play with.
Old Rabbit