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.
My second misson was to make lv 10 and get over 300 sg(I did the mission and I sent screen,please check it ) - the first was accepted after I did a topic ..now I must to do too..