A 2D multiplayer sniper io game with power-ups is titled Kugeln.io. And including up to 8 other players, you should fight to the death on a variety of maps.
There are three options available:
Compete with everyone else on the map in conflict. Having the greatest score earns you victory.
Match Death by Team
Red and blue are the two teams that compete against one another. Avoid attempting to murder your teammates! The group that scores the most wins!
Grab the Flag
Similar to Team Death Match, although to win, you must carry your opponent's flag to your own. Whoever has three captures first wins!
Use A/D to maneuver your character, and space to leap. You can use your mouse to aim. Use the left mouse button to shoot, and the right one to hurl a grenade. When you are close to a machine gun, press E to fire it. You have locate that firearm on the game and pick it up once again in order to reload your gun. And keep an eye on your health whatsoever times!