[throwawayReply]

The Steam integration is nice if you have a couple of other people who also play these games because you get to compare your best with their best.

Personally I managed to keep up with the global optimums early on in the shenzhen campaign but as it went on my solutions were progressively worse than the population. (Or least the portion of it left still completing those puzzles.)

The personal satisfaction is still the main driver of course, I think having the base binary "solved or not" solution is a good way to gate progression as you can choose to optimize as you go through or do a success pass and then revisit for optimisations which suits different play styles. (Personally I like to optimize as I go).