Here is the full list of all 18 Idle Cave Miner achievements.
Reach Max Tier on 20 Miners.
Reach Max Tier on 10 Miners.
Reach Max Tier on 5 Miners.
Clear Floor 1000 of the 'Dragon Mountains'.
Clear Floor 1000 of the 'Scrapyard'.
Clear Floor 1000 of the 'Caves'.
Clear Floor 1000 of the 'Coal Pits'.
Visit the 'Dragon Mountains' for the first time.
Visit the 'Scrapyard' for the first time.
Clear Floor 500 of the 'Caves'.
Reach Max Tier on 1 Miner.
Unlock 20 Miners.
Clear Floor 250 of the 'Caves'.
Clear Floor 100 of the 'Caves'.
Unlock 10 Miners.
Visit the 'Coal Pits' for the first time.
Unlock 5 Miners.
Unlock 1 Miner.