Updated March 31, 2021: New entries added by Jon Mundy

The .io games genre might just have had its day, if the drying up of the once constant stream of new entries is anything to go by.

There was a time just a couple of years ago when the .io genre was the hot ticket in mobile and browser-based gaming. You could barely walk down the street without some larger being threatening to gobble you up.

Perhaps some explanation is in order here. The .io genre generally consists of simple online arena-based games, in which the name of the game is to survive and grow.

It all started with a browser-based game called Agar.io from Brazilian developer Matheus Valadares. The .io name came from that particular domain name.

Its simple, massively multiplayer, every-person-for-themselves gameplay started a wave of imitators and alternatives, and thus the informal .io genre was born.

More recent examples have folded in all manner of influences from other genres, from battle royale (which seemed to develop in tandem) to whatever other genre was the flavour of the month.

Have we missed your favourite .io game for iPhone off this list? Let us know in the comments below.