Ninja.io is an online HTML5 game and 100% of 320 players like the game. In Ninja.io, you will never worry about not having an opponent. Those online friends from all over the world will become your teammates or opponents. The battle was intense and fast. There are two modes to choose from. If you like to achieve a high score sense of accomplishment, you can choose Deathmatch mode. If you like teamwork, Capture the flag mode is your best choice. Do you want to pass the boring time? You might as well try this stickman combat game. How To Play Ninja.io: AD or left/right arrow to move. W or up arrow to jump. X to prone. E to throw a grenade. Q to swap weapon. Left click to shoot. Right-click to fly.