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