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'm working on upgrading to level 3, because many exchanges require level 3. I want to ask if it's necessary to upgrade after level 3. It's painful for me to upgrade.