the game

optimal group size: 1 - 20
every child plays: one run per child
the child that plays next gets the control-flow ball.
the child walks along the track, knowing and using the building blocks.
sometimes the child will need the help of the group (subroutines), during the subroutines the ball stays on the block where the subroutine was called. when the group-play is finished, the child continues with his/her ball.
the game has to be prepared
reset variables
check conditionals and if/else branches
reset the lookup table
ideally the game is set up in a way that after the game is finished, the room is changed in some way (i.e. some work has been done, e.g. painting, furniture, windows, curtains, etc.)