Monster Train

1. 
   S-imp-le!

   Play an Imp card.
   91%
2. 
   Early Survivor

   Defeat the first boss.
   97%
3. 
   Level Up!

   Level up any clan.
   88%
4. 
   Is That a Challenge?

   Start a Daily Challenge.
   23%
5. 
   You Died!

   Lose a run.
   87%
6. 
   The Breaker of Horns

   Reach Level 5 on The Hellhorned.
   70%
7. 
   Hellhorned Dominance

   Reach Level 10 on The Hellhorned.
   38%
8. 
   A Semblance of Sentience

   Reach Level 5 on The Awoken.
   67%
9. 
   Fully Awakened

   Reach Level 10 on The Awoken.
   36%
10. 
    A Vicarious Remnant

    Reach Level 5 on The Melting Remnant.
    37%
11. 
    An Endless Flicker

    Reach Level 10 on The Melting Remnant.
    24%
12. 
    Guardian of the Styx

    Reach Level 5 on The Stygian Guard.
    53%
13. 
    Stygian Defender

    Reach Level 10 on The Stygian Guard.
    27%
14. 
    A Wisp Reanimated

    Reach Level 5 on The Umbra.
    49%
15. 
    Penultimate

    Reach Level 10 on The Umbra.
    27%
16. 
    Igniter of Pyre, Savior of Hell

    Achieve max level on all clans.
    20%
17. 
    The Hellhorned

    Win a run with all covenants enabled on The Hellhorned.
    5.2%
18. 
    The Awoken

    Win a run with all covenants enabled on The Awoken.
    5.2%
19. 
    The Melting Remnant

    Win a run with all covenants enabled on The Melting Remnant.
    5.6%
20. 
    The Stygian Guard

    Win a run with all covenants enabled on The Stygian Guard.
    4.8%
21. 
    The Umbra

    Win a run with all covenants enabled on The Umbra.
    5.2%
22. 
    Only Determination

    Win a run without collecting any artifacts.
    3.3%
23. 
    Angel Hunter

    Defeat Fel.
    82%
24. 
    Seraph the Defeated

    Defeat Seraph.
    81%
25. 
    My Game, My Rules

    Create a Custom Challenge.
    5.2%
26. 
    Upgraded Champion

    Upgrade your Champion twice.
    91%
27. 
    Trainee of the Pyre

    Score at least 30,000 points in a Daily Challenge.
    12%
28. 
    Apprentice of the Pyre

    Score at least 40,000 points in a Daily Challenge.
    7.4%
29. 
    Master of the Pyre

    Score at least 50,000 points in a Daily Challenge.
    3.6%
30. 
    Hell’s Finest

    Have a monster deal at least 60 damage in one hit.
    87%
31. 
    All Brain, No Brawn

    Have a spell deal at least 120 damage in one hit.
    76%
32. 
    Dante’s InfernoSecret

    Steam withholds the description of a secret achievement.
    38%
33. 
    It’s a Secret...Secret

    Steam withholds the description of a secret achievement.
    25%
34. 
    Thief! Stop!Secret

    Steam withholds the description of a secret achievement.
    7.0%
35. 
    The Long Journey Begins

    Win a run at Covenant 5.
    34%
36. 
    The Devil is in the Details

    Win a run at Covenant 10.
    21%
37. 
    Hell Hath No Fury

    Win a run at Covenant 15.
    14%
38. 
    We Were Born of Monsters

    Win a run at Covenant 25.
    8.0%
39. 
    The Ragtag Bunch

    Win a run with 10 or fewer cards at the end of the run.
    5.3%
40. 
    A Cramped Train

    Win a run with at least 40 cards at the end of the run.
    7.2%
41. 
    Guided by Candles

    Unlock The Melting Remnant.
    53%
42. 
    Into the Deep Sea

    Unlock The Stygian Guard.
    81%
43. 
    Diabolical Automation

    Unlock The Umbra.
    65%
44. 
    Creators of Hell

    View the credits.
    14%
45. 
    Buy Something, Won't You?Secret

    Steam withholds the description of a secret achievement.
    3.9%
46. 
    Dead-alus

    Defeat Daedalus before his combat phase.
    14%
47. 
    Li-Fel-less

    Defeat Fel before her combat phase.
    18%
48. 
    Sans Seraph

    Defeat Seraph before his combat phase.
    26%
49. 
    How to Deckbuilder

    Win a run with 0 cards at the end of the run.
    1.6%
50. 
    On Your Own

    Win a run without a Champion.
    5.0%
51. 
    20/20 Vision

    Win a run with googly eyes enabled.
    6.4%
52. 
    Ta-ta Talos

    Defeat Talos before her combat phase.
    12%
53. 
    Archpocalypse

    Defeat Archus before his combat phase.
    11%

Names, descriptions and icons are the game’s own, as Steam publishes them; the share is how many owners have unlocked each, from Steam's global figures for 53 of them.