Here is the full list of all 12 Tiny Rails achievements.
Upgrade 50 cars of any rarity.
Earn 1,000,000 gold.
Collect 45 train cars of any rarity.
Purchase 75 train stat upgrades.
Buy 400 cargo items from Markets.
Take 250 VIP Passengers to their destinations.
Visit 250 Stations.
Take 1,000 Passengers to their destinations.
Collect 30 rare train cars.
Earn 25,000 gold by selling cargo at Markets.
Upgrade 100 Stations.
Travel 1,000,000 km/622,000 miles.