UPDATE 17th Dec 2018: Kingdom Hearts 3 director Tetsuya Nomura has responded to the recent leak, saying the biggest spoilers are not yet in the game.
Specifically, the game's epilogue and secret movie will be released "at a later date", Nomura said, which suggests they'll be downloadable content of some kind. Perhaps day one DLC?
Nomura also called on people not to share leaked videos of the game that emerged over the weekend after copies of the game popped up for sale on the Facebook Marketplace over a month before launch.
Here's the statement in full:
"We're aware that a small portion of Kingdom Hearts 3 has been circulating online before its official release. We are also aware as to how this has all happened. We're sorry to see this caused concern amongst our fans who are excited for the release.
"The whole team has been working together since yesterday night (Japan time) to investigate what we can do to better this situation, but first we would like to ask that you do not share these videos.
"The game's epilogue and secret movie, which are the biggest spoilers in this game, are planned to be released at a later date just in case, so they will not be shown before the game's release.
"We want everyone to be able to equally experience the full game after its release, so we ask for your continued support on this matter.
"We're also very grateful that our fans have been warning each other already about the spoilers. Thank you very much.
"We're one month out from the release, Let's enjoy the game together when it releases on January 29, 2019.
- Director Tetsuya Nomura.
ORIGINAL STORY 15th Dec 2018: The Kingdom Hearts 3 community is doing its best to avoid spoilers after at least one copy of the game changed hands and gameplay hit the internet.
Heads up, Kingdom Hearts fans:— Nibel (@Nibellion) December 15, 2018
The full version (!) of KH3 appears to be out in the wild (some screenshots and videos exist that I won't share here)
But yeah, be careful on both social media and YouTube pic.twitter.com/6QKhu31IaZ
This damaging leak comes over a month before the game is due to launch officially, on 25th January 2019.
Footage of the title screen, install screen and more are online now after a person was seen to be selling multiple copies of Kingdom Hearts 3 via the Facebook Marketplace (listing now deleted).
A brief gameplay video was posted to YouTube as a warning to Kingdom Hearts 3 fans to avoid spoilers (there are a few swears in the video). Mods on r/KingdomHearts have threatened to ban those who ask for a copy of the leak, post a copy of the leak or link to another site which has leaked materials.
We're used to video games breaking their street dates, but this Kingdom Hearts 3 leak comes six weeks before the game is due out, which makes it unusual. We've asked Square Enix for comment.