itch.io

If you update the core mechanics, there should be an option to go back to version 1.0 or at least a "CLASSIC MODE" from the title screen.

Of course, you can always put online leaderboards on this website. Maybe. I don't know a lot about Itch.

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.