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.
Piano tiles 2 is a good game because its has a lots of fun stuff and you dont need wifi at all to play this game so thats why i play it all the time when im flying or im going on a road trip and i think everyone should play it :)...