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 remember when I played this game first, I played some time, but overall the p2w system is too big and it's not fun...So I stopped but now I didn't play a while so I don't know if it is same or worse...But I think p2w is there still.