The hottest indie game is about breeding cats with ADHD and dyslexia

When the Mewgenics team announced in 2024 that it had added autism to the list of disorders the game’s cats could inherit, developer Edmund McMillen — best known as the co-creator of Super Meat Boy — was unprepared for the reaction.

“It was like the most positive response I’ve ever had to anything I posted,” he says. On Reddit and TikTok, fans expressed gratitude and excitement for the inclusion. “Everybody was like, ‘This is the perfect representation for autism. I feel seen,’ etc., etc.,” McMillen says. “That felt like somebody opened the door and said, ‘Go on. Go ahead, do your thing.’”

Mewgenics, which launched for PC on February 10th, is the year’s first surprise indie hit. Announced in 2013, it was originally a Team Meat title from McMillen and Tommy Refenes; McMillen saved the project after it was put on hiatus. A darkly funny and deceptively complex combo of adorable characters, roguelike gameplay, and tactical roleplaying, Mewgenics is, as the pun in its name suggests, a game about breeding and bloodlines. It’s currently Steam’s top-selling game this week. Co-creator Tyler Glaiel told IGN it took less than three hours to recoup development costs, while McMillen tells noti.group the game is already expected to top 500,000 units sold. “It’s blown past anything I’ve ever done by a mile,” he says.

The game’s arrival in 2026, when misinformation about disorders like autism is rampant and pro-eugenics attitudes abound, is eerily topical, albeit accidental. McMillen, to be clear, has not created an intentional commentary on the state of the world. “I hate politics,” he says. “It’s a game about cats fucking, you know what I mean?”

There is a deluge of mutations and disorders cats can inherit in the game — from bad gas or kidney stones to ADHD and depression — that impact their stats. ADHD gives players only seconds to make decisions or the cat will start acting on its own. Autism includes accelerated intelligence but lower charisma; the cat will be naturally very good at the abilities they’re born with, but other skills might be a little more difficult. “I’m very well versed in this,” McMillen says. “I have two children that are on the spectrum, and I have a wife who is as well. … It has been a big part of my life for the past 10 years.”

Mewgenics includes over 100 disorders — name one, McMillen says, and it’s probably in the game — but each has its own silver lining. The point isn’t to immediately dump cats with certain disorders, but to appreciate them. “I want people to play and read between the lines,” McMillen says. “I want you to have a cat with autism, and instead of throwing it away, realizing its strengths and embracing the challenge and potential that that cat would have.”

Mewgenics is a personal project for McMillen, one that haunted him for years when it was unfinished. “I fell in love with the characters, and I fell in love with the world, and I fell in love with the things that I thought were interesting and fun about the genetic aspect of it,” McMillen says. The game’s road to release has been over a decade in the making; following their success with Super Meat Boy, he originally conceived the project with Refenes. While the original project was about cat breeding and the genetics involved, McMillen says, it wasn’t actually much of a game. “It was like a toy, a little idle game where you would breed your cats, and then you’d use your cats in minigames,” McMillen says.

After 18 months of development and a public showing at PAX, however, McMillen says that Refenes’ enthusiasm for the project had waned. “It was very apparent that I was the only person that wanted to continue working on the project,” McMillen says. “And I can’t force somebody to just continue to work on something.” The pair decided to put the project on pause to work on another Super Meat Boy project.

To McMillen’s surprise, he received an email from Steam expressing condolences about the game’s cancellation. After talking with Refenes, McMillen says, it became clear that Mewgenics would never happen while he worked at Team Meat. When McMillen left Team Meat in 2016, he took Mewgenics with him.

After teaming up with Glaiel, the two spent another six years reworking it into the massive game it exists as today; Glaiel did extensive amounts of research into breeding — and inbreeding — to work out the finer points of the game’s main mechanic. Felines can be any sexuality, and how their relationships progress is sometimes out of the player’s hands. “They can be very passive,” McMillen says. “They can have rivals. They can fall in love. They can be rejected.” Online, he’s said the game will take most players over 200 hours to finish.

Writing Mewgenics has made McMillen regard some of his previous work differently. He points specifically to The Binding of Isaac and its themes on nature versus nurture and “how nurture can really fuck a kid up.” Some struggles in life, however, are inherited.

“The game definitely became more about children — the experience of raising children,” McMillen says, reflecting on how fatherhood changed his view of the game from its inception to release. “The legacy that you leave, and the genetics that you pass to them and curse them with. I started to write more from that perspective.”