UPDATE 9/2/18: Less than two days after release, Shadow of the Colossus fans have solved the puzzle behind the 'Enlightenments' added to the PS4 remake.
Beware the following contains spoilers for those hoping to work on the mystery themselves.
As suspected, finding all 79 collectables scattered across the game's map unlocks a reward - a sword hidden within a cavern underneath the starting temple area.
You can watch PS4Trophy's moment of discovery at the 2 hour 22 minute mark:
The weapon is the Sword of Dormin, named after the mysterious entity that guides Wander throughout the game. Equipping it reduces your health regeneration, but increases your damage output significantly.
And with that, the mystery is seemingly solved - though players are now wondering if you can use the sword for something else. We'll report back if anything develops.
ORIGINAL STORY 6/2/18: After fans have been searching years for one last big secret in the original Shadow of the Colossus, the PS4 remaster comes with a mystery of its own.
Outside of the 16 Colossus to defeat as part of the main story, the original had two sets of optional collectables to find - Fruit Trees and Lizard Tails - both of which also feature in the PS4 remake.
The remaster has introduces a third type of collectable, which have been dubbed 'Enlightenments' or 'Gold Coins' by players, which glow and sparkle when found.
Unlike Fruit Trees and Lizard Tails - which increase your health and stamina gauges respectively - the purpose of these Coins is currently unknown.
There isn't a Trophy associated with finding them, nor are they mentioned as part of the in-game stats summary found from the pause menu.
However, once you find your first Coin, they are logged in the bottom corner of the map screen as a number that increases with each subsequent find.
How many of these collectables are there? A video by PS4Trophies theorises a total of 79, based on a message in the end credits, thanking the "Nomad Colossus and the 79 steps to enlightenment".
A total of 70 has been found so far, so if the theory is true, we won't be waiting long for the mystery to be solved.
Could there be something hidden away at the end of those coins, or will finding them all simply be its own reward?
That's not the only new addition introduced as part of the remaster, with an Easter Egg for another Team Ico game to find off the beaten path.
Shadow of the Colossus releases tomorrow (February 7) on PS4. While you wait, you can read our Shadow of the Colossus review as well as Digital Foundry's analysis, describing it as one of the best remakes of all time.