In many io games with a survival theme, you have to kill other players and eat food to make your character stronger. If you do this over and over, you will get to the top of the list. Most IO games have these things:
A big online area for playing with other people that has a competition scoreboard.
There are simple rules that make it easy for anyone to play. People who get bigger by eating food and sometimes other people.

There are times when you can play with other people, but most of the time it's "survival of the fittest."
Newest IO Games: IO games have grown a lot and now have a lot of different games, from first-person shooters like Shell Shockers that smash eggs to survival battle royale games like Voxiom and Zombs Royale that put players against zombies.
Two of the newest IO games are Smash Karts and Ev io, a first-person shooter that looks like it was made in the future. Pixel Warfare and Cubes 2048 are two of the newest and best IO games you can play.