The potential here is pretty huge. When I saw the light ball I thought about how there could be areas with floating crystals and other strange creatures, crystal caverns with streams and waterfalls...
That this is an early first version of the engine is encouraging. Imagine it after several iterations in future games? I hope Obsidian can build on P:E, refining the engine over the years.
Request: Would there be a possibility to toggle day / night, or to peg the day / night cycle to the users pc time?
I know that's a kind of meta-option and assumes the world's days are 24h, but I always found BG etc most immersive when I was in a dark area when I played at night in a dark room, totally absorbed.
Great demo, vast potential.