In Fish.io, you find yourself at the bottom of a virtual ocean, which, thanks to its excellent graphics, looks very realistic. Well, your main character is a small fish (at first you can choose one of two), which needs to grow and become stronger. At the same time, the task is not to get caught in the teeth of other predators. Therefore, to begin with, eat whatever you can, for example, plankton or krill. Well, as you grow older, move on to larger specimens and grow exponentially.