This would have to be dumbed down to the point where it just isn't fun anymore.
But, I played this game some months ago and it was incredible fun. Here are a few nice contraptions:
A friend made this "Retard Plow"
Fantastic Contraption: A fun online physics puzzle game
Here are some of mine.
Nukem, the car...thing that could.
Fantastic Contraption: A fun online physics puzzle game
Simply titled "o." I should pitch this idea to Chevrolet.
Fantastic Contraption: A fun online physics puzzle game
Trifecta.
Fantastic Contraption: A fun online physics puzzle game
Best of all, Fido
Fantastic Contraption: A fun online physics puzzle game