Steam accidentally made a normally hidden data type public: achievement lists for upcoming and even completely unannounced games. The result is one of the largest gaming leaks in recent memory.

How Did the Leak Happen?

x3sphere, owner of trophy and achievement tracking site Exophase, explained on ResetEra that this appears to be a "possible error on Valve's end." Normally confidential achievement data for many games became accessible through the Steam API, and Exophase's systems automatically indexed this information. That’s how both announced and never-before-seen projects surfaced at the same time.

The Biggest Names: Persona 6 and Kingdom Hearts 4

The most eye-catching games in the leak are Persona 6 and Kingdom Hearts 4, both still at least a year away. If the Kingdom Hearts 4 achievement list is accurate and up-to-date, it reveals details about Disney worlds and Square Enix story elements that haven’t been made public. The Persona 6 leak is even more surprising, since the game has only been teased with a single, non-revealing trailer so far. Atlus has not officially confirmed any of the leaked details. Persona 6 was reportedly announced in June 2026 with no release date, while some sources noted that Sega’s Japanese site previously listed a 2027 launch window.

How Widespread Is the Leak?

According to Gematsu, the leak covers more than 30 games, including both announced projects and previously unknown titles. Other highlights include Dragon Ball Xenoverse 3, Attack on Titan 3, Final Fantasy Resonance, Deus Ex Remastered, Thief: The Dark Project Remastered, and Tomb Raider: Legacy of Atlantis. The leak also exposed 15 completely unannounced games, such as a new Sonic title, a new Star Wars shooter, and a Telltale The Walking Dead collection.

Other Affected Games

The achievement list for Mega Man: Dual Override includes references to Robot Masters that haven’t been officially revealed. For story-driven games like Gears of War: E-Day, the achievement descriptions may hint at key story moments developers wanted to keep secret until launch.

How Reliable Is This Information?

The existence of achievement data does not guarantee that every listed game will launch as shown. Achievements can change, be removed, or renamed during development. Still, these leaks can spoil information developers intended to reveal gradually, so story-driven gamers may want to avoid looking at these lists to preserve surprises.

Frequently Asked Questions

Was This Leak a Hack?

No, current information suggests this was a configuration error in Steam’s API, not a hack.

Has There Been Official Confirmation About Persona 6 or Kingdom Hearts 4?

No. Neither Atlus nor Square Enix has officially confirmed the accuracy of the leaked achievement lists.

How Many Games Were Affected by the Leak?

The reports mention over 30 games, including 15 previously unannounced titles.