io games traditionally refer to games with sites that end with the domain ".io". Nowadays, iogames typically refer to multiplayer browser games io games became popular with the release of Agar.io. It had simple gameplay and graphics, as compared to the mobile and computer games of the time. Regardless, Agario drew many online players which made the game super popular. It spawned a lot of clones that show up every day. The next majorly well-received io game was Slither.io. And after that, an io games trend began. Titotu has the most complete list of io games and keep it updated.
— Simple and fun gameplay
— Multiplayer, and team play, with many online players
— Easy to begin and learn, since the games are usually have continuous gameplay
Unlike mainstream "freemium" games, io games are absolutely free, full gameplay is available without extra payments. Some io games are also available on iOS and Google Play stores.
You might consider io game running on any device since it's browser game, but you'll be mistaken. Since game runs inside browser it heavily uses devices resources. So on an old computers the games might be laggy. To avoid those you need not very old computer and a high-speed network connection. If the game still lags, try exit full screen mode. Also in some games you can reduce graphics quality.