Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
For someone who wasn't in time for Gamehag's new giveaway :)
#JP04-9J7DY-D0W70 ;
Just replace the # with the missing letter.
P.S. Many thanks to the creator of this group for the opportunity to share the keys here! And thanks to those who contribute here, too.