Despite growing in scope since it first appeared, Call of Duty's Zombies mode remains just another component of the CoD games. Some might wonder why there hasn't been a standalone entry in the series outside of the mobile games--after all, plenty of zombie-slaying games have been successful. But there's a reason that hasn't happened with Call of Duty.

Speaking with Eurogamer, campaign and Zombies mode director Jason Blundell explained that the studio has "to cater for a lot of people." And many of these players like to move between all of the modes on offer.

"Sometimes you want to watch a movie and want to be engaged narratively on a concept," he said. "And then we have multiplayer--sometimes you just want to run around and have that high-engagement experience. And sometimes you want to kill the undead--sometimes you want to play Zombies.

"We see by the numbers and how people engage with the game as a whole, people change that feeling. They'll move between the different modes."

That'll be easier to do than ever before in Black Ops III. There is now a unified version of the games that allows you to seamlessly move between the campaign, Zombies, and competitive multiplayer. You can even stay with the same party while moving between the various modes, all of which support online multiplayer.

Blundell went on to say the team behind of Call of Duty is "always about giving as much content, as much value for money, as we possibly can. That's why we pack our disc with as many game modes as we have currently."

"It's really about flexibility and variety of choice for the amount of people who buy our games," he added.

Black Ops III's Zombies mode features a celebrity cast comprised of Jeff Goldblum, Heather Graham, Neal McDonough, and Ron Perlman. The latest trailer, which you can watch above, introduces us to each of their characters as they commit various murders.

Black Ops III lacks a campaign mode on last-gen platforms, but does include multiplayer and Zombies. You can read more about the game in our recent interview covering the many choices you'll have, as well as one discussing the campaign's "twisted" story.