Popcorn Party

Difficulty: Medium-Hard

Popcorn Party is an achievement unlockable for GOTY, iPhone, iPad, PS Vita, Android, and Nook editions of Plants vs Zombies.

Strategy
In the iPad/iPod Touch/iPhone/Android version, you can play the first level where Gargantuars appear in Quick Play. (5-8) Bring the Cob Cannon and Kernel-pult, as well as Sunflowers, Twin Sunflowers, Cabbage-pults and Flower Pots. Dedicate the remaining seed slots to a combination of defensive plants, such as Wall-nuts and instant kills (though preferably not the Potato Mine).

When playing the level, start with your Sunflowers normally, adding a column of Cabbage-pults in the furthest Flower Pots. Upgrade your Sunflowers as you can to Twin Sunflowers, then build as many Kernel-pults and Cob Cannons as possible. Continue doing this throughout the rest of the level. Try to not to rely to heavily on the Cob Cannons, however, as you must save corn cobs for the Gargantuars when they appear. But don't shoot a Corn Cob at him when he's in the third column as he'll toss his Imp to eat every single Sunflower, but use 2 Cob Cannons to fire at him before he throws his Imp. You need to be fast to fire the second missile immediately after the first one or the Imp will be thrown, attacking your plant at the back.

When a Gargantuar does appear, weaken it with an instant kill, and then quickly fire one of your Cob Cannons at it. Do the same thing for the second Gargantuar, and you will obtain the achievement with ease.

Survival: Endless is also a good idea. Plant Sunflowers like you normaly do, then plant the Kernel-pults, then any other plants of your choice. When done, if you have enough for Cob Cannons, go for it.

Any Survival: Hard mode can work the same way.

Note: It is also possible that you can obtain the achievement "Defcorn 5" by using this method.

Note: The Cob Cannon has to get the kill, or else it won't count.

Strategy 2
Pick up these plants:

1. Sunflower

2. Twin Sunflower

3. Flower Pot

4. Cabbage-pult

5. Kernel-pult

6. Cob Cannon

7. Potato Mine

8. Squash (for the first zombies, not for the Gargantuar)

In the beginning of the level plant two columns of Sunflowers. Then for the first zombies use Potato Mines/Squashes, then build a column of Cabbage-pults and Kernel-pults for the first wave. Then save the sun to buy Cob Cannon. It must be built on two Kernel-pults. Build as many Cob Cannons as you can. When the first Gargantuar comes, fire two cobs at him. Do the same with the second Gargantuar and you will easily get this achievement.

Trivia

 * This achievement can be obtained by killing two Giga-Gargantuar.
 * Playing Buttered Popcorn will not get you this achievement.
 * The reason is because there is usually only one Gargantuar. Also, although there's a (small) chance that you might see two Gargantuars in the Mini-game, you cannot earn this achievement after you destroyed two as the achievement tells you to purchase Cob Cannon.
 * This achievement, No-Cob-No-Explode and Defcorn 5 are the only achievements that involves Cob Cannon.
 * Inside the Android version, you can only get the Achievement on either level 5-8 or 9, as they are the only levels where both Cob Cannons and Gargantuars can encounter each other.