I kinda like it, too. I like your examples. You could make levels with tasks like: Put the ball on the box. Or: Let the first ball role under the jumping ball to the box. Still not that much.
What about adding sounds to the different movements and collisions?

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt