This is a hidden feature in the game that it blocks several achievements and many have difficulty understanding how it works. In this post we will make it crystal clear how you can unlock the mods by using the codes in the achievements. Codes is a series of 5 gems of different grade shown in some achievements like below, we will mention later the entire list of them. Also, note that the gem codes are randomly generated so you will have to do the combinations yourself.

First of all, lets see how someone could find out about the codes. This is shown in the initial screen of the game by hovering the credits. At the bottom of the credits we can see the algorithm of code combination. It shows that the code is a combination of 3 series/achievements, it starts and ends with the grade 1 gem and the next series starts with the first 2 gems being the same as the 2 last ones of the previous achievement. The codes are images of gems with grades ranging from 1 to 12. The result is an 11 gem code. The example will use the grade level of each gem (no images).
Example: 1 3 2 4 2, 4 2 5 7 9, 7 9 11 10 1
Result: 1 3 2 4 2 5 7 9 11 10 1

Achievements with codes:
Armored Orb
Dry Puddle
Double Strike
A Shrubbery!
Fully Lit
Double Sharded
Glitter Cloud
Bye Bye Hideous
Not So Fast
Come Again
Vantage Point Down
Ages Old Memories
What Are You Waiting For?
Blue Wand
Connecting the Dots
Black Blood
Round Cut
By Three They Go
Mana Trader
Come Out, Come Out
Century Egg
Forged in Battle
Your Mana is Mine
Early Bird
Is Anyone in There?
Can’t Stop
Feels Like Endurance
Out of Nowhere

There are 12 mods so you will find 36 unique codes, 3 per mod. You will find them at the top of the map, after unlocking them you can click on each of them to enable/disable. Now we know where we can find the codes, how to calculate them and what they enable but there is one missing part, where do we insert those codes?

At the bottom of the map, there is a list of buttons, each with a gem of grade from 1 to 12. Those are visible after you beat E4. Let’s follow our example which resulted in 1 3 2 4 2 5 7 9 11 10 1. This is the order you need to click the gem buttons, first the grade 1 gem, then the grade 3 gem, etc. After you clicked the entire sequence calculated from your achievement gem codes successfully, a popup will appear informing you which mod is unlocked. Now you can enable the mod from the top border of the map!

GemCraft Frostborn Wrath – Achievement Gem Codes and Mods