But you can get most of those things already. Shirts can be ordered with custom prints. You can rent (or buy) a bouncy castle and put it in your backyard. Beddings and sheets I get, because you can probably only find them in twin sizes.

Light-up shoes in adult sizes on the other hand are nearly impossible to find, or are pretty expensive if you find one.

Saw a kids sweater with a fuzzy dinosaur on it recently. Thought it would be amazing as an adult sweater. But of course it would cost $400 if it existed

Clothes with dinosaur/unicorn/etc designs

What do you mean?

Snow boots that change color in the cold. I had those as a toddler and they were the coolest things ever.

Bedding and sheets with fun prints

• Technically there's no one and nothing stopping you from buying Pokemon bedding, for example.

Clothes with dinosaur/unicorn/etc designs

• Also, cute clothes have been trendy since MLP:FiM at the earliest.

I've been in a bouncy castle with kids and alone. It sucked and I was very tired.

Maybe if there were some full-size humans bouncing they would bounce me around too instead of me launching kids onto the roof.

There was an art show that had a bouncy castle for adults. I think that's a thing

Exists:

I’m very interested in where you are sourcing this list!