Here’s a design for kids: a bunk bed based on the Velociraptor cage from the first Jurassic Park film. The box shape and ladder make for a perfect bunk bed.
It features a sliding door that allows access to the lower bed. You could make lift gates at both ends of the bed to match the cage, but I think that would make getting in and out of bed rather annoying.
Some lighting would be helpful for the lower bunk too, if only to recreate the “Raptor getting tased” scene!
I didn’t think of this until now, but several drawers and cubby-holes can also be implemented throughout the bed frame, to help store junk and such.
In summary, the greatest parents ever would make this for their kids.