Back From The Future 3 is an achievement in Plants vs. Zombies 2. It requires the player to plant Thyme Warp three times in the same level. It is worth 10 points on Game Center for iOS devices and 1,000 XP on Google Play Games for Android devices.
Its name is a reference to the Back to the Future trilogy, with the first two movies being filmed in the 1980s, while the third and final movie was filmed in 1990.
Play levels like Neon Mixtape Tour - Day 10 or Neon Mixtape Tour - Day 19 which are Special Delivery levels, where multiple Thyme Warps can appear easily. You can also imitate the Thyme Warp to use it three times easily. Additionally, you can use Plant Food to instantly recharge it assuming you have the Instant Recharge upgrade. Another good strategy would be to stall zombies using plants like Iceberg Lettuce, Stallia and Chard Guard to give you more time to wait for Thyme Warp to recharge. It is suggested not to try gaining this achievement on a normal level, as Thyme Warp has a very slow recharge. But if you have Instant Recharge you can use that to recharge Thyme Warp and get this achievement.
One more good method is in final wave, leave a Basic Neon Zombie alive and shovel all of your plants. Let him eat an Infi-nut. After he has done, plant a Spring Bean behind the Infi-nut. These 2 plants can help you have an indefinite time, which should be enough to wait for Thyme Warp to recharge. This combo can also be perfect for levels that requires the player to produce a certain amount of sun.
- The number "3" in the achievement's name may probably come from the way to obtain the achievement.