I've been mulling over stuff for an update to the game, and whether or not to delay introducing new features until I've gotten a more substantial package ready. Regardless, leaderboards are definitely something that I want in a future version.
Don't forget there are always websites to create leaderboards. Here's one for Graveyard Shift, made by me:
https://keepthescore.com/board/lpchrvvpbrxke
If you don't like it, I will be OK to take it down.