At Hole.io the goal is to swallow whatever you find along the way to grow. You have to start with the smallest elements and then continue to eat always, while gaining size.
In the different scenarios presented, everything is edible, from people to buildings, through plants, poles or rubbish bins and including opposing black holes. You have to have a mouth for that or, rather, a hole.
You can choose to play in three modes: Classic, where the objective is to finish the race ranked first against the various opponents, Solo Run, which, as the name implies, is a fight against time alone, and Battle in which you have to be the only one surviving black hole.
Hole.io is free and available from both the Play Store and the App Store, respectively for Android and iOS devices.