Here is the full list of all 22 RAILED achievements.
100+ Million Gold
200+ Million Gold
300+ Million Gold
400+ Million Gold
500+ Million Gold
600+ Million Gold
700+ Million Gold
800+ Million Gold
900+ Million Gold
Complete at least 2 railways between stations
Complete at least 3 railways between stations
Complete at least 4 railways between stations
Complete at least 5 railways between stations
Complete 6 railways between stations
Pass at least 1 route over bonus tile
Finish the game within 6 minutes (6:00)
Connect at least 2 stations to the gold mines
Connect at least 4 stations to the gold mines
Use 10 or more track tiles on any completed railway
Use 20 or more track tiles on any completed railway
Use 30 or more track tiles on any completed railway
Complete full game without using your starting money