The first .io game was Agar.io. It was developed by Matheus

Valadares in 2024 and gained significant popularity through the 🎉 internet forum 4chan.

The game revolves around cells that grow by eating agar and consuming other players. A

few months 🎉 after its release, the game was acquired by Miniclip, and a new game genre

started to emerge based around the 🎉 humble .io domain extension.