You load sixteen tons, and what do you get?
Another day older and deeper in debt.
I've completed The Company Store, a game about going deeper and deeper into debt. It's also about mining, but the mining is coincidental and not intended to relate to the "deeper and deeper" theme.
It's a match 3 game with a bit of strategy to it.

I've balanced the game so that it's basically impossible not to rack up more and more debt, until you eventually go to debtors' prison. I guess the goal is to last as long as possible, arcade-style. This all makes sense thematically, but in retrospect making a game where the best thing you can do is not be in as much debt as you might otherwise have been is probably not great for making the player feel like they're accomplishing something...