ManOrMonster.io is a nice Multiplayer game that lets you choose your favorite team to play, including the human side or the monster side. You will join a fierce battle between these two teams. If you belong to the monster team, you must go kill enough the humans to set off the Ar-man-geddon. But if you are one of the humans, you have to destroy enough monsters and defend your planet. Be sure to gather the green points so you can reach the top of the leaderboard!