In Greek mythology Styx was the river between Earth and the Underworld. In this mobile puzzle game the player helps the ferryman to transport the souls of the dead over the river and into the kingdom of Hades. This is not as easy at it sounds since the river is full of barriers that block the path for the ferryman. The aim of the game is to clear a passage through the river so that the ferryman can row his boat from shore to shore. The gameplay works like a sliding puzzle, similar to the board game Rush Hour, and the player uses the touch screen to drag the barriers around the playing field. For each movement made the player has to pay a coin to Hades but for each completed level he is awarded 100 coins. After completing the game the player can compare his score to others on a global high score list.