how do remove the save file and restart the game from scratch?

So I have bought all pets, but number 9 does not show up in my pet inventory, and I can not get the achievement, cause the shop says I have bought it. any way to fix this?

Maybe I missed it, but what does completing a monument do in game? Do you get any bonuses from them?

Is this achievement broken? It says to collect 5000 gems and I have 6000 and it's still locked.

Multiple times across different holes i've watched the workers pop back up from the mine with no dirt and then deposit the no dirt at the monument and go back to digging along with the fact that the worker ai for holes is absolute trash for clearing the floors in any consistent manner where it takes forever....