After humanity's extinction, the world is taken over by strange creatures called "Mushlooms." They live a dependent life, always relying on humanity's old work and inventions, but remnants of humanity's past lead to a contagious outbreak among the mushlooms. This outbreak causes innocent civilians to transmute into dangerous beasts known as "Monslooms." As you work to reverse the outbreak, many creatures including different variants of Monslooms approach you. You must strategically place and use your party members in a chess inspired battle system to result in victory.

As the number of Monslooms increase, the size of your party increases as well. Each party member has a unique action to solve puzzles whether it's throwing others, shoving others, shooting, hacking, and more. Combat is divided into two sections. The first is the party's turn, with each party member being based on one of the 6 piece types of chess. You must use these to your advantage by placing the members to deal the most damage to enemies. The second section is when the enemy attacks a party member. You take the control of the member and dodge the enemy attacks in a 2D platformer style.

In this Action RPG, you must grow stronger, solve puzzles, learn about the world, and move on from the past to save your species from extinction.