This is a really cute game and I had a lot of fun playing it together with a friend and designing a bunch of different playgrounds.
Of course I could complain about wanting more features and options, but that'd be a little silly for a jam game that was made in 10 days. I'm impressed you were able to do as much as you did in that short time. The graphics are cute and the game runs smoothly, so it's a great way to spend a few spare minutes to relax.
Here's the playground I built: