Is that what the goal is? I've had so many goals that I didn't realize were intermediate goals until afterwards.

I was thinking the ultimate goal would be to find the edge of the map and wall everything off.

(I still haven't met my goal of really understanding rail signals)

I also wonder if there isn't more in store. For example, I don't see what paving and reinforced concrete floors are for. Will there be wheeled robots, or (sigh) burrowing beasts that can go under walls?