We've done it twice.
you listeen to a talk about plastics, hands on touchy stuff. Then you go in, and you build a robot on the computer - choosing head, body, legs, good for hot, good for cold, good runner, good jumper. Then everybody races their robots, by running on the foot pad.
Then you get to go build a robot, using set pieces. All the robots essentially look the same, just different colors. ANd a I think 2 sytles of legs. BUt free.
my boys had fun, and I worked up a sweat.