How much does it cost to play Alien Worlds?

Excuse me, could you please clarify the cost structure for playing Alien Worlds? Are there any upfront fees or in-game purchases required to participate? I'm interested in joining the platform but want to ensure I have a clear understanding of the financial implications before diving in. Additionally, is there a way to earn or generate in-game currency through gameplay, or is it solely reliant on external investments? Thank you for your assistance.