The io game genre all began with the release of an insanely addicting game called (which was probably inspired by another game called “Osmos”).
Agario grew so fast that within months, it was already seeing several hundred thousand players worldwide.
What made this io game so unique was it’s very interesting style.
Unlike most browser games of the past, it was designed to be played in a fullscreen browser window, and was entirely multiplayer.
This set the framework for many of the other games that would hit the web in the months to come.
Most fun and successful new io games like slither.io, agar.io, and follow these general guidelines: Slitherio is a good example.
It's a very simple game, with easy-to-use controls.
There's no experience required to begin playing, meaning people can get the hang of it very quickly. The simple, clean graphics are also worth mentioning as a relevent characteristic of the genre.
After I found the first few popular io games, I tried to find more.
Sadly, without a list, they were really hard to find.
I felt that they deserved more exposure, so I decided to create my own list.
I put together all the titles I could find, and many helpful users shared new ones with me.