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