This program is pretty nifty. 
It’s like a 3D Platformer game where the levels are created by everyone and shared online. I got into the beta the other day and have been having a ball ever since. 
Right now it’s fairly limited in terms of customization.
You get three packs of level pieces that you can mix and match in each level; the Adventure Pack, the Forest Playhouse Pack, and the Sand Castle Pack. Each pack contains props, hazards, blocks, moving platforms, connector platforms (staircases, bridges, and ladders). Just a fun game overall, hopefully will be a little more extensible by the time the final version is released. I’d recommend trying to get into the beta.
Just signed up for it. Let’s see how many months it takes for me to get the invitation
Oh yeah, I am in the beta for this too. It’s definitely nifty, and I look forward to seeing what they do with it. I hope they introduce more in the way of customisation. It’s good that it is so cross platform though, with mac, PC and Linux support.