The stomp rocket launcher works really well, but a few out of box modifications are necessary. First of all, the fins are needed to improve the flight of the rockets -- however, the stickers don't hold the fins to the rocket at all. One really needs to use a stronger tape to hold the fins on, and while scotch tape is a better solution than the included stickers, its still not perfect. Secondly, the lime green foam toppers don't always sit and stay within the straws, so that the rockets launcher becomes a "cannon" instead, with the foam top as a projectile. Its still super fun, but not really ideal for the purpose of the "experiments." Thirdly, I've had the straw portion of one of the rockets break (slitted, like when a drinking straw accidentally gets bent and splits) after a couple of launches. When everything works, however, its super amazing and super fun, and I considered it a win that my kid understood the concept that the higher one aims, the less far out it goes, etc. And the kites are a lovely component as well!