
Simply taking the series back to WWII isn't going to be enough to rejuvenate the dwindling fanbase. Call of Duty fans want something new and exciting. Introducing an in-depth siege mode (one more detailed than Headquarters or King of the Hill) where players must protect their safehouse while trying to infiltrate their opponents', or even a simplistic create-a-map mode might be enough to regain some traction with fans.

Although being very similar to it in a visual aspect, being developed by the same.

If Activision can create a new mode that is equally as innovative and captivating as the original Zombies, it could breathe new life into the series. Call of Duty: World at War (Nintendo DS) is a first person shooter video game for the Nintendo DS created as a Nintendo DS version of Call of Duty: World at War, based on its predecessor, Call of Duty 4: Modern Warfare (Nintendo DS). It made the series more than just another WWII shooter because some people found Zombies more appealing than some of the franchises' campaigns. Being constantly bombarded with new Call of Duty titles with little to no innovation can drive away even the most dedicated fan. The original Zombie mode in Call of Duty World at War became an overnight sensation.

It's been over 15 years since fans haven't seen a yearly release from the iconic franchise. Taking a year or two off might help revive interest in the series.
