To unlock this achievement you will have to survive at least 40 Flags, however the achievement won't actually unlock until the Zombies eventually break through at whatever level you can reach. What you have learned in Adventure Mode will be useful for Survival, however in later waves the strength and cunning of the Zombie hordes will become extremely overwhelming and your only defences will be planning, strategy and efficient control. Below I have chosen the top two most efficient and easy methods to follow. There are certain musts and must nots in surviving at least 40 waves but there isn't one single most effective way. To complicate things the Endless Survival Mode is set in the Backyard with the pool and this cannot be changed.

Unlike Adventure Mode you will have the option to choose any ten plants every two flags and you will not encounter any bonus waves (like Wall-Nut Bowling). Although you can pause and quit to save your game at any time you cannot restart from flags or checkpoints and if you're too slow or clumsy and make too many mistakes you will have to restart from flag one. With Endless mode unlocked you then have to survive no less than '40' flags (which is 20 levels) of Zombie hordes in succession in that mode.

This achievement involves firstly completing enough of the lesser Survival Modes to unlock the Endless Survival Mode (follow my guides for various scenarios in the 'GENERAL HINTS AND TIPS' section if you're struggling with any of them).

Plants vs zombies 4