Google’s home page logo is moonlighting as a strategy card game on Friday. 

If you click on Friday’s Google Doodle, celebrating the lunar cycle, you’ll go into a click-to-play card battler that turns the moon’s eight phases into your own personal combo deck. In the game, called Rise of the Half Moon: May, you play against the moon to link matching moon phases, chasing specific card combinations to get more points. If you outscore the moon, you move on and can snag wildcard power-ups for the following rounds, where the game progressively gets larger and more difficult.

This interactive doodle, which marks the Flower Moon’s final half-lit quarter, is just the latest entry in Google’s recurring Half Moon series.

Google Doodles began in 1998, and over the years, they’ve ranged from simple sketches to interactive games and puzzles, but this is certainly one of the more intricate ones in recent months. See 53 of our favorite Google Doodles here.

Not sure how to start? Here’s what you need to know.

What exactly is May’s half moon?

May’s half moon is the month’s third-quarter phase, which is the moment when the moon has orbited three-quarters of the way around Earth and sunlight illuminates exactly half its disk. It’s the final quarter, or “half moon” phase of this month’s lunar cycle. This year, the half moon occurs on May 20 at 4:56 AM PT. From the northern hemisphere, you’ll see the left side glowing, and in the southern hemisphere, the right side shines.

This month’s lunar cycle is dubbed the Flower Moon, because it coincides with the colorful wildflowers that bloom across North America and Europe this time of year.

Check out these knockout shots of the Flower Moon as taken by NASA astronaut Nichole Ayers on the International Space Station.

How the Flower Moon game works

The Rise of the Half Moon starts out on a three-by-three grid. Each turn, you choose one of three random moon-phase cards and place it on the board. Here’s how you score points:

• Pairing phases: Drop two identical cards side-by-side (one point).
• Making a full moon: Combine complementary phases — example: waning crescent plus waxing gibbous (two points).
• Completing a cycle: Lay cards in the exact lunar order, new moon through waning crescent (three cards or more, one point per card).

If you beat the moon three times in a row, you’ll unlock a monthly wildcard with a special power in the game. This month, you have four wildcards up for grabs, as long as you clear all nine boards. As you move on, the layout begins to grow beyond the three-by-three grid, and the game exponentially gets more difficult to win.

How to play (and actually win)

To play the game, go to the Google homepage and click on the doodle. The game will load in a pop-up. 

Next, scan the board. Lines connect the squares, showing how you can link them for combinations. You should plan your placements on those pathways. 

Then, finally, play a card from your hand. You’ll always have three cards, but you should always think ahead. The moon, who’s your opponent, will use your cards against you, so you should think not only about offense but also defense when you place your card.

A few tips from playing:

• Play defense: Defense is just as important as offense. If you sense that the moon is planning a large combination, you can use one of your cards as a throwaway to block the combination from occurring.
• Use your wildcards: Wildcards can wipe out enemy cards, steal cards or duplicate your cards. Use them only when needed, especially during the later, more difficult levels, because you can only use them once.
• Make your moves quickly: You get only a handful of turns per round, so don’t chase every combo. Secure the highest-value plays as soon as you can.