kugeln.io is a 2d multiplayer shooter. You have to fight to death on various maps together with up to 8 players.
How to Play kugeln.io
Control your character with A/D and space to jump. You can aim with your mouse. Shoot with the left mouse button, and use the right one to throw a grapnel. Press E when you are close to a machine gun to use it. To reload your gun, you have to find that weapon on the map and pick it up again. And always have a look on your health!