The player must dig down 666 meters (and collect 50 coins along the way) in order to reach Hell (for some reason or other) using an axe. The player must keep an eye on their health, oxygen, and energy meters, along with avoiding torches, lava, and various denizens on the way to Hell.
If you're able to make it down to hell, you can actually dig past it. Don't speak to the bouncers and start digging...but you'll have to dig to the side, rather than straight down the middle, as there's lava right underneath hell.