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.
Should you aim to buy game-chest here or buy keys and games at the shop directly? What is the best use of gems? Chest or buying something that has a set price?