Balls.io is a free Android game developed by FIRE STUDIOS. It falls under the category of puzzle games and is a fun and engaging game to play. The game's objective is to eat small balls to grow bigger and solve puzzles along the way.

The game is simple to play, with just a tap to move the ball. As you move around the game, you consume smaller balls to grow in size. The larger you become, the more challenging it is to move around and avoid obstacles. The game has a variety of puzzles that you need to solve while growing your ball.

Overall, Balls.io is an easy-to-play game that can become challenging as you progress through the levels. It's a great way to pass the time and test your puzzle-solving skills.