Wouldnt say fun but definitely compelling, spent an hour playing it.
There is nothing to do but crafting and creating platforms, that said creating an MMO for a Jam and seeing other players building is amazing. The controls are a bit confusing i threw most of my stuff at first so it takes some fiddling before you can start to create.
Ok, lets build the last building so i can call it aaaaand... i obliterated the whole world, woops...