Actually, there is moderation. The problem is that the page came to HN before I added the moderation keywords or implemented more things :P But overall, it's possible.
On the details like benches and trees, you can also customize it. YOu can add as many props as you want, wherever you want, and style them accordingly. :)
Love the idea, I added to my site!
I know it might be too much to ask for, but it would be great to have the ability to add your own props, like an icon and how to animate it. I would love to add maybe cats or drones icons that also move around!
That's also coming! It's already in the roadmap since the beginning. I'll add some of those props myself, but I'm working on a plugin architecture so people can add their own stuff.