The player has to again deal with tons of zombies with the given plants. Though the tiny zombies are weaker, they are much bigger in numbers making them a nuisance.
This means that Wall-nuts will not be as in much importance as before (though they are still crucial to pass the level).
Strategies
Try to aim for at least two Peashooters in each row and a column or two of Wall-nuts to defend the Peashooters. These zombies, although they take little effort to be killed, spawn in big groups to make this level difficult.
If your plants cannot hold up by the amount of zombies, Lawn Mowers and Pool Cleaners temporarily will take care of the grass lanes or pool lanes for defense.
It is possible to lose fairly quickly since the plants are random. The player might get too many Lily Pads and unable to win the level.