(I would like to finish my comment but just to prevent excessive downvotes...) It’s cool (at least to me) that a software can simulate the physics world fast & accurately. It makes some interesting ideas pop out of my head, e.g. making some flip/flops and compose them into a basic 8-bit CPU and simulate.

Overall it’s similar to where people get excited with minecraft. I’m pretty sure people who upvoted this article also has some interest in minecraft.