Diep.io

Diep.io is a 2D massively multiplayer io game published by Miniclip and released in 2016. It is available to play in a browser with the URL diep.io, as well as a mobile application available for iOS and Android devices.

Gameplay
In this game, the player controls a simple Tank and shoots powerful Bullets, Drones, or Traps at Polygons and other tanks to level up and Upgrade their tank to the next level.