This is a really fun take on the theme, I was really impressed with how fleshed out the game seems to be, with many screen for unlockable and different eras! I loved the music speeding up and changing in the last 40 seconds.
I think this game really needs a tutorial on what tools do what however. I first used the shovel and it was going to take 20 seconds, but then the pickaxe took more time than the total round? This seems like a pretty deep game and I would love to see it get expanded out with a proper tutorial!
Amazing job!