Here is the full list of all 24 SteamWorld Dig achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Dig out 15000 tiles.
Get all four gold stars in the same playthrough.
Complete the game in less than 2 hours, 30 minutes.
Complete the game with more than 20000 gold collected in total.
Complete the game with more than 150 orbs collected in total.
Complete the game without getting killed once.
Immortalization of a destructible steambot.
Find all secret areas in the caves.
Find and sell 16 Dark Matter ores at the same time.
Reach the bottom of the world.
Maximize all upgrades.
Destroy a laser box.
Crush 10 enemies with falling blocks.
Destroy two generators before entering Vectron.
Defeat 10 mecha trilobites before they wake up.
You found Vectron!
Buy from all of Tumbleton's shops.
Find and sell 8 Uranium ores at the same time.
Defeat a turtle submerged in water.
Defeat 10 shiners before they wake up.
You found the Old World!
Defeat 10 trilobites before they wake up.
Find and sell 8 Trashium ores at the same time.
You found Archaea!