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