Cute wall shelf for my son's bedroom

I saw this plan posted and knew I had to have it for my son's new bedroom. Most of the build was simple, it just got a bit tricky fitting in the angle piece at the top because I wasn't sure how to attach it without having a nail gun. Every time I line it up to nail it in with a hammer it would slip a bit. So I ended up using Gorilla Glue Epoxy to attach it. Since it's not hanging on the wall by the very top shelf, I didn't need it to be rock solid to support any weight, just needed it to stay in place.
I had scrap plywood laying around so it was free for me to make.