Beghouled

A minigame, based on Bejeweled.

Plants

 * Peashooter
 * Wall-nut
 * Snow Pea
 * Repeater (Upgrades Peashooter)
 * Puff-shroom
 * Fume-shroom (Upgrades Puff-shroom)
 * Tall-nut (Upgrades Wall-nut)
 * Starfruit
 * Magnet-shroom

Zombies

 * Zombie
 * Conehead Zombie
 * Buckethead Zombie
 * Newspaper Zombie
 * Screen Door Zombie
 * Football Zombie

Strategy
Just switch the plants to make matches of 3 or more, upgrade them as you go along, and try to make Combos. Period.

Note: If you are unable to find any match, the match(plants) which is possible glows.

If none of the plants are glowing, then text will come screen saying that no more matches are possible.

That is the time when you need to shuffle your plants.

Diamond Beghouler
Upgrade all of your plants to get the achievement.