My dad bought these for all his kids this Christmas — when I opened it I thought it was a joke. I mean I really thought it was a toy for little kids, but he pulled up some videos on YouTube and I was pumped to put this thing together.
The assembly is tricky and you need a helium tank, but once together this is simply awesome.
I spent at least an hour playing with it at my dads, one of my cats is scared to death of it — best toy ever.
(Side note: We tried taking one outside and it floated away rather quickly. If you do this a fishing line tether is a smart play. Also achieving perfect neutral buoyancy is key.)