Not OK Corral

Not OK Corral is a Brain Buster exclusive to Wild West. There are ten waves of zombies on each level. The players get a new plant before each wave, randomly picking a card that results in a plant. The first two levels have a locked order of the plants, while the third level has a random order past the seventh plant. Players can know the types, numbers and positions of zombies too. They require a bit of strategies and good memory to beat these levels.

Levels
The Roman numerals are the the level numbers before the 1.7 update, while the parentheses show where the level is located after the 1.7 update, or if the level is removed in the update altogether. Each level has one flag, ten plants, and ten waves of zombies.

Trivia

 * In Not OK Corral III, when the player has planted the Coconut Cannon, tap on the Spectate Lawn button to see the zombies, then quickly tap on the Coconut Cannon to awaken it. The Coconut Cannon should destroy some of the zombies on the screen, making it a good strategy to pass the level easily. This was fixed in the 1.7 update.
 * After the 1.9 update, these levels allow the player to use Power Ups.
 * This might be because the game was hard without them.
 * If the player has acquired Wall-nut First Aid and repairs a Wall-nut with it, the wave will not start.
 * This Brain Buster's name is a reference to the Showdown at the O.K Corral.
 * No levels have 2 flags.
 * No Plant Foods are given, except the player buy an additional one or more.