Here is the full list of all 15 Train Harder achievements.
Kill 10 bandits.
Have you unlocked the secret mode ?
Kill 50 bandits.
Kill 100 bandits.
Kill 500 bandits.
Achieve a score of 100.
Achieve a score of 250.
Achieve a score of 500.
Stay on the train for a duration of 30 sec.
Stay on the train for 1 min.
Stay on the train for 2 min.
Kill a passive bandit.
Successfully teleport yourself without loosing a bone.
Achieve a score of 750.
Achieve the extra-ordinary score of 1000.