Algodoo

For marble races... DUH Save the entire save other than the plane at the bottom as a stamp/phunlet to make the beggining of a marble race out of these marbles (you can use the scale tool if all the marble sets you could find are not to scale with the marble size, Select the whole thing then use it to scale everything down, Scale this part down for optimal preformance and less lag during the prossess)