Bloble.io is a 2D strategy game that has minimal graphics. bloble.io unblocked
Kazap.io game is played with your spaceship floating through vaccuum of space. You utilize the arrow keys to move as you wish freely all around, however, you must be aware of your sorroundings as touching a wall will kill you.
Agar Wtf is a widely popular 2D online action game. In this game, players command a "cell" which looks like a ball.
Celestia.io is a 2D multiplayer game in which you are a furry ball in floating around in outer space.
Battle! Combat Strike 6 is a cool multiplayer online first individual shooter by a99 Games.