My memory is EXTREMELY foggy on this so bear with me.
- You could generate shapes like squares and rectangles, as well as axles, gears, and I THINK belts.
- You could designate sources of power and pick which object it was driving.
- The website had a place to submit videos of your creations, and I think even competitions.
- They had their own YouTube channel.
That's all I can really remember. Sorry I can't be more specific, but I already tried searching the forum cause I know it was mentioned here, and maybe even had a topic.