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.
From what I remeber, have around 400+ hours in warframe but I left because of the shear lack of content. But with the new update I'm thinking about getting back into the game. Is it worth it?