Undead Space

Difficulty: Hard

Undead Space is an achievement unlockable for the iOS game versions. In order to complete it, the player must kill 10,000 zombies and then scroll to the edge of space on the Leaderboards screen. The player can keep track of your kills by going to the online achievements list.

Strategy
To earn the achievement, at least 10,000 Zombies have to be killed in any way. The player's pile on the online page accumulates as he or she kills Zombies.

Good choices

 * Last Stand
 * Column Like You See 'Em (kills about 400 zombies each time)
 * Survival: Endless (when it is released for iPhone)
 * Zombie Nimble Zombie Quick
 * Wall-nut Bowling 2
 * Whack a Zombie
 * Last Stand: Endless

To check your pile, click on Leaderboards icon on the main page, and scroll up on the pile or tap the top of the screen until you reach the top. You don't have to be signed into Game Center to see your score.

Trivia

 * At 1,000 zombies, the player can see the Balloon Zombie's Balloon.
 * When the player gets about 12,000 zombies, he or she will see the moon from Peggle Nights, another game from PopCap.
 * When the player gets about 16,500 zombies, he or she sees space rocks, or more exactly, asteroids.
 * At around 23,000 zombie kills, the player can see gems from Bejeweled, another PopCap game.
 * The limit is 30,000 zombie kills. After that, the zombies are sucked in a black hole and the pile doesn't get any higher (although the player's kills are still recorded).
 * Letting any zombies die in I, Zombie will not increase the player's count.
 * The name of the achievement is a reference to the video game Dead Space (the un- prefix likely comes from the fact that the player fight zombies in Plants vs. Zombies and zombies are undead).
 * Many armored zombies still have their armor. Also, The Poles used by Pole Vaulting Zombies are damaged.
 * In this pile, the player can see Zombie, Flag Zombie, Pole Vaulting Zombie, Newspaper Zombie, Conehead Zombie, Football Zombie, Buckethead Zombie and Snorkel Zombie. Many of these Zombies have X's on their eyes replacing the pupils.
 * It's called Undead Space because the player reaches space when he or she kills 10,000 zombies.