GoBattle.io is one of the best .io games:

Play for free with your friends in this retro-inspired arcade game. Collect the coins to upgrade your weapons, buy new skins, and to become the new King! But be careful with the enemies and the creatures that you will find in your way!

There are three available game modes:
* King mode: Free for all multiplayer battle.
* Damageball: Team match football with a poisonous ball. Competetive matches.
* Battle Royale: Survivor mode. The last warrior alive will be the winner!