ShootEm.io offers a fun deathmatch for free, with traditional top-down views as well as excellent gameplay mechanics.
You can also use the map to find melee or ranged weapons. You can also drive vehicles to stay out of danger and battle enemies. You can keep your character safe by controlling it with the WSAD keys or fighting with the left mouse button.
ShootEm.io lets you enjoy yourself and play a multiplayer deathmatch.