If you're lacking something to shoot this weekend, here's a decent option: the multiplayer component of Call of Duty: Black Ops 3 is free to play between now and Sunday afternoon (from 10AM PST on Thursday until 1PM PST on Sunday, to be precise). Publisher Activision is also offering 33% off the standard edition of the game and 20% off the deluxe edition.
The free offering is actually the new Black Ops 3 Starter Pack, which was released last week and offers a stripped back, multiplayer-focused version of the full game. The pack provides access to ranked multiplayer with a level cap of 55, as well as access to the weapon paintshop, gunsmith, emblem editor, arena and freerun modes, theater and the black market. Alas, the Starter Pack has no zombies.
That Starter Pack is only available until February 29, so if you fancy Call of Duty without the overblown singleplayer campaign you'd best act quickly. Once you've purchased that, there's an option to upgrade to the full version of the game, which, y'know, has zombies.