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.
Start an arcade battle and then return to hangar. The game still gives you wins if your team goes on to win despite you leaving. You can have more than 1 game ongoing at the same time, as far as I know. Go get them 30 wins!