Thinking about the skyscraper idea (which is cool) I thought making cranes could be fun too. The test for a crane would be to lift a load of a certain weight and move it some distance.
The new elements CL would have to come up with would be winches. You'd probably need at least 2, one to winch the load and one to move the boom(s).
Hmm, to do a tower crane you'd probably also need rolling anchors (to hold a winch and roll along the boom to move the load laterally). Of course that could work on the base of a normal crane too.
The test might not be automatic though, you might have to click up/down buttons for each winch to control it. If that could be recorded, it could still work for contests.
Given the excellent dynamic engine they have, they could probably pull this off!
Think of the fun of having to lift a heavy load and move it over some high obstacle and let it down! Yes, I am a geek.