Here is the full list of all 30 Astalon: Tears of the Earth achievements.
Defeated the Black Knight as the Gargoyle.
Killed 5000 monsters.
Reached the top of the tower as the Black Knight.
Finished the game with 100% completion.
Completed 80% of the bestiary entries.
Purchased all character specific deals in the shop.
Purchased all of Bram's deals in the shop.
Purchased all of Zeek's deals in the shop.
Purchased all of Kyuli's deals in the shop.
Purchased all of Arias' deals in the shop.
Purchased all of Algus' deals in the shop.
Completed all entries in the bestiary.
Gathered 100% of the tower's items.
Explored 100% of the tower's rooms.
Completed 50% of the bestiary entries.
Defeated the Black Knight.
Defeated the Gorgon Medusa.
Defeated the Gorgon Solaria.
Collected 50000 orbs.
Unlocked the gorgonslayer Bram.
Defeated the Gorgon Gemini.
Completed 20% of the bestiary entries.
Killed 1000 monsters.
Collected 10000 orbs.
Unlocked the collector Zeek.
Defeated the Gorgon Volantis.
Defeated the Gorgon Tauros.
Found the secret ending.
Defeated all the bosses in the Boss Rush mode.
Unlocked all secrets in the game and beat all the unlockable modes.