Mummy Memory is a Brain Buster exclusive to Ancient Egypt in Plants vs. Zombies 2, its Chinese version and Plants vs. Zombies Online. In it, the player must tap on the signs of Camel Zombies to reverse them and reveal a symbol and match the ones of the same kind. It requires a little bit of strategy if the player just taps randomly with all fingers on both hands. The player would have to get lucky at points, and the thing that makes random tapping even more dangerous is that there are absolutely no lawn mowers, so the player cannot afford to stall. Other than that, the player can choose to use his or her memory instead. It is played on Ancient Egypt - Day 7, 16, and 23.
In the beginning of each level, it says "Ready, Set, Match!" instead of "Ready, Set, Plant!".
These levels are the only ones, besides Ancient Egypt - Day 5, that does not feature any plants. This is also the only Brain Buster where plants are not present. In both, the player is not allowed to use Plant Food since there are no plants given.
Sometimes, when the player destroys a board, there is a bug where the zombie stands in place for a few seconds and then dies when it is about to walk. This is because, in a regular level, after destroying the board, the zombie may stall for a few seconds before walking.
If the player kills the Camel Zombie where in it has already reached the player's house and starts to eat the brains, he or she will see a very thick smoke produced by the death of that zombie that will stay there forever, and "THE ZOMBIES ATE YOUR BRAINS!" without the munching sound. This trait was also shared by Zombie Chicken. If the player manages to kill it once it reaches his or her house, it will only show the feathers or none at all. The only thing the player could do is to kill it with either Power Snow or Power Zap. The same goes with a charred zombie in any of the Zomboss battle levels (only if the player has successfully defeated Dr. Zomboss).
The matches have a bit of a delay if the match is not correct before flipping back, making rapid taps a bit ineffective.
Mummy Memory and Cannons Away are the only two Brain Busters where the player cannot use Power Ups or Plant Food. This is because this level only focuses on matching and Cannons Away focuses on reaching a target score with Coconut Cannons .
In the 2.9.1 update of Plants vs. Zombies 2, the Camel Zombies suddenly appeared instead of appearing from underground, which also happened to other zombies with that effect. This was fixed in 3.0.1 update.
In Plants vs. Zombies Online, the roadcone is red instead of orange, the skull is blue instead of purple, the sun is green instead of yellow, and the bucket is yellow instead of blue. Also, the clover is absent from this game.