It starts with a pickaxe.

Click a block. Get a stone. Click again. A few hundred clicks later you can afford a jackhammer, and it doesn't get tired.

Then the machines take over

Jackhammers, steam drills, seismic hammers, excavators, mechanical worms, all the way to the Annihilator. Each one hits harder and wider than the last, and you can run a whole row of them at once. The rock gets harder the deeper you go, so they'd better.

Smelt what you dig

Ore isn't worth much raw. Build furnaces, from a stone kiln to a fission furnace, turn copper and tin into bronze, iron into steel, crystals into lenses, uranium into fuel rods. Sell ingots, or feed them back into bigger machines.

One mine is never enough

Open new sites on the world map, each in its own biome with its own ores. They all keep digging while you look at another one.

10 km down, and then up

Reach the planet's core and start over stronger with the Mastery tree. Build a launch pad, send probes and drills to asteroids, mine uranium in orbit, and wrap the sun in a Dyson sphere.

Play it at your own pace. Leave it running in a corner of the screen while you work, or spend an evening tuning every furnace and every column. Either way the mine keeps going down, and there is always a bigger machine waiting a little deeper.