This is a video of Youtuber Allen Pan (previously) constructing a bunch of inventions his subscribers (and numerous other children) invented as kids, including (in order): suction cup boots for walking on the ceiling, a laser sword, plunger grapple gun, and lawnmower boots. Surprisingly, they actually all work better than I had anticipated, which was not to work at all. I guess Allen has a little more how-to know-how than I do as far as these things are concerned. I can make fireworks from scratch though.