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.
In gamehag you have to use different accounts which is really weird, but It is because you have to have the exact username in game as in gamekit name and its impossible to have 2 gajin accounts with the same name. So it's just one of many trick they use to not give us gems. I hope this helps.