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.
It looked a lil boring at first but when I jumped into battle it just felt so cool to destroy other's cars and play with your friends. It's amazing and you should definitely give it a try!