This achievement can be found on the official Crystal Clash Steam page under the Store.
https://store.steampowered.com/app/1839660/Crystal_Clash/ Scroll down to About This Game and click the read more. At the bottom of the About section is the code.
To unlock this achievement head over to the shop in-game. Click on redeem bonus code and then copy and paste or type out in all caps in the box. Once done hit enter for an achievement.
XR0F-7ST3-4MC0-MMUN-1TYX