What are io games? 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. 我就不直接翻譯了，說下我的理解，目前玩的手遊io遊戲都是從傳統的頁遊發展來的，例如我最早玩的Slither.io(貪食蛇頁遊)，經歷了各種開發團隊模仿，加上微信小遊戲的普及讓這類小遊戲越來越火，這些遊戲的特點都是每局的時間不長，充分利用了玩家碎片時間，每天都有那麼點時間去玩所以粘性很強，而且我發現像hole.io這類遊戲讓你感覺在和真實玩家在聯機對抗，但其實我們都在跟AI玩呢哈哈哈哈！我手機裡已經裝了10+的io遊戲了。

io類遊戲發源於國外，以操作規則簡單、多人線上對抗、死後即刻復活等為特點，由於在命名時多以io結尾，久而久之也被人稱為io類遊戲，在國內又被稱為休閒競技類遊戲、大作戰遊戲。

2015年上線的《球球大作戰》、2016年上線的《貪吃蛇大作戰》則被看作是io遊戲風潮較早的引領者。