Extremely promising little sandbox game for building dioramas and rooms, as well as anything else you can think to create with blocks. Features some really awesome "smart scaling" features—for example, you can make a kitchen pot taller or wider without messing up the handles, or make a lamp taller or shorter without stretching or squashing the lamp shade. It's got some nice bonus features too, like world lighting, point lights, and adjusting the reflectiveness and paint wear of an object.

I streamed the demo! Please ignore the fact that I didn't discover the "vertical stacking" feature until the very end (I recommend checking out the rest of the tutorials section after completing the beginner tutorial so you don't miss anything, like I did): https://www.youtube.com/watch?v=mRXlmmTErf0