This one is called Rise of the Half Moon, and it’s one of those interactive card games. The premise is simple: you play against an artificial opponent and get cards to play with different phases of the moon. You get points if you match cards next to each other, or if you cards “create” a full moon. You also get points for creating a lunar cycle.

"You'll be over the (half) moon about this new Doodle game series! Join the celestial card game where players must connect the phases of the lunar cycle to earn points and against the October Half Moon. If you're skilled enough to beat the moon, you might just be rewarded.

Google is educating users about the lunar cycle with its latest interactive Doodle released Thursday. The Doodle commemorates October's last Quarter moon-- better known as a half moon because of its half-full appearance -- before the Waning Gibbous phase culminates in the New Moon.