Arkadium has been running free online games for over two decades, which is a strong sign of legitimacy. The site offers thousands of games, a subscription service, and even a shop where you can pay with Google Pay or Shop Pay. Security-wise, it checks most boxes: HTTPS, modern encryption, and no history of malware or blacklisting.
Where it falls short is the paperwork. A site that handles payments should have a clear privacy policy and terms of service posted somewhere easy to find. Arkadium is missing both. Most established game portals make these documents front and center. Their absence doesn't mean the site is a scam, but it does mean you're giving your payment info without a written guarantee of how it'll be used.
If you're thinking about buying a subscription or making a purchase, a cautious approach makes sense. The games themselves are fine, and the site has been around long enough to prove it's not fly-by-night. But before you hand over your card details, check whether they've added those legal pages. Until then, stick to the free games.