Survival: Endless

Survival: Endless is a Survival Mode level that is set in the Pool which has an unlimited number of flags. It is featured in all of the versions of Plants vs. Zombies, along with Plants vs. Zombies: Journey to the West and Plants vs. Zombies: Great Wall Edition. It is unlocked after completing all the other Survival Mode levels. This level is mainly a challenge of surviving as many flags as the player can, and will become very difficult as the player completes more flags. Just like all Survival: Hard levels and Last Stand Endless, the player can choose new plants when two flags are completed. Each time the player upgrades a plant, the upgrade's sun cost increases by 50 sun. If an upgraded plant is removed in any way, its cost will decrease by 50 sun.

Overview
The basic idea of Survival: Endless is that seemingly an unlimited number of zombies are attacking in an onslaught to take over the Player's House. The player has to hold off the zombie hordes for as long as possible, resembling the military act of laying siege to a castle. The only ways for Survival: Endless to end are by getting the player's brains eaten or if they reset.

High flag number errors
At 107,374,183 flags, only Flag Zombies will come, and no zombies will be shown in the seed selection screen, until flag 214,748,364. After that, other zombies will come, although in small quantities and increase every flag. After 214,748,366 flags, the game will go to -214,748,363 flags (due to an integer overflow), and the flag number will only show during the intermission every two flags. At -107,374,181, only flag zombies will show up, until -1 flags, where Survival: Endless will be like normal.





Strategies

 * See Survival: Endless/Strategies.

Tips

 * A good setup is plenty of Cob Cannons, a column of Winter Melons three squares from the house to slow down the zombies, a column of Gloom-shrooms in front of the winter melons because Imps usually land there and they can get rid of them. Spikerock can distract the Gargantuars. While placing Tall-nuts can protect the Cob Cannons.
 * You can also use Gatling Peas with Torchwoods instead of Winter Melons, though it will not slow down zombies but deal more damage.
 * Despite all Survival: Endless builds winning on Survival: Pool (Hard), not all Pool: (Hard) setups can take the large zombie amounts on Survival: Endless.
 * Zombonis, Jack-in-the-Box Zombies, and Giga-gargantuars are the true threats on this level. The Zomboni can crush the player's plants and cannot be slowed, while the Giga-gargantuars take four instant kills to die. Both can be stalled and killed with Spikerock, but the Spikerocks need to be replaced quickly in most levels, which is problematic due to Spikerock's slow recharge. Jack-in-the-Box Zombies rarely are a problem, though they can occasionally blow up instantly and wipe out plants in the pool.
 * Be aware that you cannot kill Giga-gargantuars in Plants vs. Zombies FREE, as only lawn mowers can kill them, meaning that you have no hope into winning the round without hacking.
 * It is recommended to protect everything possible with Pumpkins as one will never know when a zombie might get past one's defenses.
 * The back four columns of the Pool are the safest area for Cob Cannons; as long as the plants in front of those rows are protected by Pumpkins, zombies that surface during waves will not be able to get back to them. If a Pumpkin is planted on the plant in the fifth column, its wider hitbox will allow Zombonis, Catapult Zombies, and Giga-gargantuars to crush it more easily. If a Pumpkin is not planted on it, it is safe from those zombies. However, Football Zombies may eat the plant.
 * The player should rate a setup by the amounts of Cob Cannons he or she has.
 * Zero to three: Bring many instant kills, have plenty of powerful attacking plants.
 * Four: Bring a couple of instants, keep Cob Cannons away from the offense.
 * Five to eight: Instants might not be used, but if you have extra spots use them. Keep Cobs protected.
 * Nine and more: Instants will be rarely needed, but keep a Doom-shroom or some other high range plant(s). Keep a cycle going with Cobs.
 * If one doubles up on Winter Melons, only do so on land. Thrown Imps sometimes draw fire from Winter Melons long enough for zombies to unfreeze. Winter Melons do the same amount of damage as Melon-pults, so the player should not plant too many.
 * Every time the player plants an upgrade plant, its cost increases by 50 sun.
 * However, if an upgrade plant is destroyed in any way, its cost decreases by 50 sun.
 * Gloom-shrooms or other plants with area of effect attacks are recommended, even when dealing with Digger Zombies or Imps.
 * If the player uses Cattails against Balloon Zombies, Blovers can also be chosen for every two flags in case the Cattails are distracted and a zombie sneaks past. However, this should only happen if the Cattails are near the front of the pool or on one side of the pool.
 * Large amounts of money can be earned through progression in this mode. Even if one misses many coins, he or she will get $30,000 or more within ten flags of Survival: Endless.
 * The amount of zombies will stop increasing at around 100 flags.
 * Ice-shrooms are very important here, especially if you are not using Cob Cannons; if timed correctly, it can prevent ambushes. Use this to your advantage. Imitating it is a better idea.
 * Obtain a lot sun of during the beginning, as you need it to plant your expensive, powerful plants. Obtain about 9000 sun so you will rarely have a lack of sun. Even if you have a lot of sun already, it is not recommended to dig up all your Sunflowers and it is advised to have at least two Twin Sunflowers in the entire setup.

Trivia

 * Bungee Zombies only appear during huge waves in this stage.
 * In this game mode, the ambush Ducky Tube Zombies appear one tile closer to the left.
 * In the PC and iOS version of the game, when the player checks the Suburban Almanac, the upgrade plants sun cost will still appear with a plus sign (+) beside it. That means each times the player uses them, their cost will increase for 50 sun.
 * This is the only level that includes Giga-gargantuars in the PC version.
 * The Zombie Bobsled Team and Dr. Zomboss are the only zombies in the Suburban Almanac that are not in this level. This is because Dr. Zomboss would most likely ruin the entire game if he was included in this mode. The Zombie Bobsled Team does not appear for an unconfirmed reason, even if a Zomboni has made an ice trail for the Zombie Bobsled Team.
 * This is the only level where upgrade plants increase and decrease cost in sun depending on the player's flag number.
 * There is a mode in Plants vs. Zombies 2 similar to this called Endless Zones, but the player's planted plants don't exist in the next level, not all of their plants are there at the start, and levels can have 1-4 flags. The player also only get four default plants, but get to pick more as the levels go on.