One of the most entertaining multiplayer IO games is Snowball.io. Toss snowballs at other players and try to be the last one standing to win the game.

Gather snow by moving around. As the snowball develops in size, it becomes easier to annihilate your icy foes. Toss your snowball at other players once it’s ready. The snowball will also be used to attack and knock down players.
Tips play : 

• Earn XP and unlock new skins
• Play in tournaments and quick-play mode
• Fun, fast, and addictive gameplay!
• Simple controls

How to play

Hold down the left mouse button to move and form a snowball, then let go to shoot.