I was at a friend's house, and played a little $1 game for the 360 called "Miner Dig Deep".  You are a little miner dude, and you make tunnels and elevators to go deeper and deeper in the mine, so you can get resources, so you can upgrade your equipment...

The whole game is very zen, as the only way you can die is via a cave in or falling down a shaft.  If you die, you lose what minerals you are carrying, but pick right up and go back at it.

It is a simple, but addictive, formula.  Sadly the indie publisher has released no information regarding a PC version because of a lack of a publisher (get on that Stardock!).  I really want to scratch this itch, but can't find a good replacement.  There have been multiple similar games, like digdug and motherload, but they lack the whole sandbox, zen, epic feel and are more about avoiding death as you go along.

Any suggestions?