"Special Ops: Head to the Lunar Landing base to defeat a bunch of robots and robot Zombies!"
Agent Citron informs the player of Dr. Zomboss' robot army, and instructs the player to destroy the army. Thus, the player will head to Lunar Landing, where they must plant a garden and hold off 5 waves of zombies. There is no special wave in this mission, but the fifth wave is always a boss wave that includes a single Mech Gargantuar. After defeating the zombie hordes, the mission is completed and the player receives their reward.
The zombies in this mission comprise mainly of future-themed Browncoat Zombies, future-themed Conehead Zombies, some Foot Soldier variants, Future Imps, Robo-Zombies and an occasional Computer Scientist. Thus, a versatile team must be chosen so that both the large groups of Browncoats and the high-health Robo-Zombies can be taken out easily.
The Mech Gargantuar at the end can be somewhat tough to handle. It is recommended that the player seeks out the Mech Gargantuar and destroys it, as usually the AI can handle the hordes of zombies attacking the garden.
Citron variants are good choices for this mission, as their EMPeach can help with the groups of enemies, their primary weapons do a good amount of damage and the Peel Shield combined with their high base health make them difficult to vanquish.
For the AI-controlled characters, at least one Sunflower and exactly one Kernel Corn is recommended. The last character can be any character, although Chompers are less suited for this mission. Kernel Corn has extremely high damage output and the Butter Barrage can also eliminate the hordes of zombies, making him an ideal choice for this mission. Sunflowers are simply there to keep everyone healthy and also give some support to whoever is defending the garden. The last character will be the main plant in defending the garden for the boss wave.
Note that Kernel Corn variants will actively seek out bosses. With the Kernel Corn and the player, the boss should be reasonably easy to take care of. Meanwhile, the Sunflower and whoever is the last character will stay back and hold off the hordes.