Hexbug Vex Catapult

Hexbug Vex catapult – check prices at Amazon

Explained as a stem toy for ages 14+ well you would be better off mastering the intricacies
of thermodynamics if you really want to be an engineer!

Could be quite fun for the elder sibling to launch younger/brothers smaller toys out of the
upstairs window once they get bored of catapulting the balls around.

Converts into a couple of other toys also.

Cheap enough price for your kid to have some fun with.