It's cool and oddly, flowing, I think the ability to only control using the mouse makes this unique. It feels a bit inaccessible because it just starts, out of nowhere, gives an impression more of a sandbox rather than a game with levels.
that was originally a goal but then saw how much joy my little brother felt trying to beat a random test level I had been working on
makes perfect sense!
with sandbox you mean theres many parks/levels that you can choose without having to completing the others?
In my personal opinion i prefer it with levels.