lurkers.io is a multiplayer browser game with similarities to Garrys Mod. Everyone can host their own server and script their own gamemodes, so there isn't necessarily 1 particular aim to the game.
You can play the game here right now without any registration: http://s3-ap-southeast-2.amazonaws.com/lurkers.io/index.html
I've just added some motion blur to particles and projectiles, let me know what you think!