Agar.io is a puzzle game where you compete with others.

The game features an original concept - you absorb other players' spheres while you protect your own. If another player has a sphere that's bigger than yours, then it's likely that you will be absorbed as well.

All that you do to play is drag your sphere around the screen. If you see a sphere that is smaller than yours, then you absorb it. Each time you absorb the smaller spheres, your own sphere gets slightly larger. Your goal is also t not be absorbed by the bigger players, but you are free to start over if it happens.

This game certainly offers you a competitive environment and a fun way to compete with other people. If you manage to survive, then you'll also have the satisfaction of winning the game.