Zombie Army 4 feels like an old friend you're reconnecting with after a few years. Even though it's similar to its predecessors, the game has been refined into something that holds greater mass appeal. Weapon upgrading, fresh enemy design, and a packed progression system give players a reason to keep coming back. The core gameplay loop is even better more when tackled in co-op, yielding some hilarious and action-packed adventures. Despite the good, the game's core issues arise from a bland campaign that lacks the impressive set pieces and locations from the previous iterations.