“The Binding of Isaac” creator Edmund McMillen’s latest project — a multiplayer card game called “The Binding of Isaac: Four Souls” — raised over $1 million on Kickstarter in just over a week.

The game has three 100-card decks — monsters, treasure, and loot — all featuring the disturbingly cute “Binding of Isaac” art style. Kickstarter backers who donate $25 or more get a copy, which includes the three decks, bonus cards, custom dice, a rulebook, and more.

So, how does “Four Souls” work? Each player chooses a specific character card, three loot cards, and three pennies. Everyone takes turns playing the loot cards and attacking monsters to gain resources used to purchase items. Eventually, they’ll take on bosses and collect their souls. The first person to gain four souls wins.

We hit 1,000,000!!!! You guys unlocked the stained glass sticker!! This semi transparent sticker will now be included in All game boxes! Thanks so much for spreading the word! And we did it in just over week! https://t.co/7HXKOlcCir so much more to come! pic.twitter.com/9Vug6Fyb3n — Edmund McMillen (@edmundmcmillen) July 7, 2018

“The Binding of Isaac” came out in 2011 and has reportedly sold over three million copies across multiple platforms. It helped revive interest in “roguelikes,” a video game genre notable for its procedurally-generated levels and permadeath.

McMillen said digital media company Studio71 approached him over a year ago about doing a possible “The Binding of Isaac”-themed product. He blew them off at the time, saying he was busy with other projects and didn’t have any ideas.

“Fast forward nine or 10 months,” he said. “I was sick with the flu, stuck on the living-room couch, bored out of my mind when the basic structure for a ‘Binding Of Isaac’ card game started taking over my brain. Within five days I had roughly 200 cards, drew them up and started testing things with [his wife] Danielle.”

McMillen plans to release “Four Souls” in November.