While on a hunting trip, Björn's village was attacked by powerful monsters. Soon Björn realised that these monsters were so powerful that normal weapons could not harm these creatures. Only a weapon blessed by a god could kill them, and to get such a weapon he has to sacrifice something. As he only had his bow and some arrows with him, he has to sacrifice parts of his body. 

While playing the game you can walk using WASD, turn with your mouse and shoot by clicking left the mouse button. But be careful, because shooting costs you health. In the dungeon you will find an altar that allows you to sacrifice loot dropped by enemies for health. After completing the level you can play the endless mode.