Okay, so this achievement is to beat all the mini-games in PvZ.
**To unlock mini-games: complete the adventure mode, then beat the mini games which you have, to unlock more.**
You beat the mini game when you finish all the flags and get the trophy.
The mini-games start off easy, but some of them can be quite challenging.
(Comment if you need help on a certain mini-game and I'll update the solution with some tips.)
The games which I found most difficult were:
**Some of these tips may seem obvious but I'm just trying to help**
When starting out, try to build shooters as far back as you can.
Use Ice-Shrooms to not only slow down zombies, but also to determine the location of the oncoming zombies.
Try to get at least 1 projectile plant (Pea-shooter etc.) in each lane, firstly focusing on the lanes with zombies.
When you are given a lily-pad try to fill it with anything asap until the pool is sufficiently defended.
Having the sound turned up helps massively, you can hear if a bucket-head is being hit or if a dolphin rider is coming.
Look + Listen for splashes in the pool.
If you can hear your shooters hitting a bucket-head, try to get more ammunition on that lane or slow them with an ice-shroom.
Try to save Squashes for emergencies, and have them in the pool to take care of Dolphin Riders.
By the 2nd wave, try to have a wall-nut in most lanes and start to work on building up the shooter/catapult plants.
The Zomboni (One which leaves an ice trail) is a pain and it is best to try and Squash him.
This one will probably take you a few attempts, but eventually you will have a good game where good plants are given.
Bob-Sled Bonanza Tips:
The main tip I have for this one is to use Spikeweed and its upgrade Spikerock (Bought from Dave's shop).
These plants instantly kill the vehicles (In this case the Zomboni, ice trail zombie)
I chose to take the sunflower and the upgraded sunflower (Bought from Dave's shop) so I had ALOT of sun.
The tall-nut, jalapeno and an imitator of the jalapeno are must haves for this one.
Use a jalapeno, to clear the ice and then try to get a spikeweed / if possible a spikerock set up at the start of each lane, where the zombies come from to prevent the lanes getting iced again.
My set-up was to have tall-nuts protecting the sunflowers with rows of spikerock in front of the tall-nuts.
On the pool, I used Kernal Pults which were good enough to keep the zombies back.
Last Stand Tips:
For Last Stand I suggest 2-4 Cob-Cannons at the back, with some kernal pults.
Each lane protected by a tall-nut.
In the pool are 2 of the Cob-Cannons and in front I used 2 cat-tails, followed by the tall-nut.
It can also a good idea to set up some magnet-shrooms, if using less than 4 cannons, (using the coffee bean to wake them) behind the tall-nuts.
By the second flag you should be able to create/have a set-up like:
Y=Cat Tails on Lilypads
For the rest of the game just try to maintain the field and make sure to use the cannons effectively.