Each round, you'll start with ten points. Click a blue card to add to your score, or a red card to subtract. Your goal is to remove all the cards without letting your score go below 1 or above 20.

Drag any card to your hold zone to save it for later. You can only keep one card at a time in your hold zone.

When you win a round, you'll collect gems. You can use those gems to buy skins, undo your last move or discard a card by clicking and sliding it over to the trash can. 

You can also try the Daily Challenge for a unique spin on the gameplay.