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.
I just completed the Walking Dead: Road to Survival quest as per the link generated. I wasted so much of my time and grinded, but what do I get? Nothing. Please fix your automated wall quests, as this is very frustating. And now, I can't do it again either as it won't be my first account. Even the support doesn't help.
Furthermore, this is not the first time. I have completed over 3 quests in total. I didn't get rewarded for either of them. Please either remove the automatically rewarding quests or fix it.