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