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