Banana Storm is an achievement in Plants vs. Zombies 2. It is achieved by completing any Big Wave Beach level by using only Banana Launchers to kill zombies. It is worth 5 points on Game Center for iOS devices and 500 XP on Google Play Games for Android devices.
Two ways to very easily gain this achievement is on either Tiki Torch-er or Big Wave Beach - Day 26. To get it even easier, use boosted Banana Launchers. Only plant them when zombies come out of the water. However, it is a very bad idea to use in normal levels due to the sun cost and launch reload time of Banana Launcher though you can use Gold Bloom for the sun issue.
Do note that since the game only requires zombies to be killed with the Banana Launcher, plants that don't damage zombies such as the Iceberg Lettuce and Sun-Producing plants can be used freely.
- It is actually impossible to not earn this achievement on Big Wave Beach - Day 26, unless Power Ups are used.
- Because of this, it is unknown why there is no specification to this on the achievement.