Here is the full list of all 20 Pharmakon achievements.
Discover what stay in blood.
Kill two beasts in one shot.
Discover what remains on top of the cliff.
Discover the black rocks facing that tree.
Kill a first beast.
Discover the rock in lake.
Finish the game to unlock Arcade Mode.
Kill three beasts in one shot.
Kill four beasts in one shot.
Kill five beasts in one shot.
Kill six beasts in one shot.
Kill seven beasts in one shot.
Kill eight beasts in one shot.
Kill nine beasts in one shot.
Kill ten beasts in one shot.
Discover a limit.
Discover how it is made.
Discover from where comes the leak.
Discover what is the meaning of this.
Finish the game without dying. Restarting the game will cancel a deathless run.