If you're mad enough to find all 79 well-hidden golden relics, you'll unlock a new area and a powerful sword that are totally unique to the PS4 remake.
Here's what happens when you collect all 79 gold coins in Shadow of the Colossus on PS4
Shadow of the Colossus (PS4): Hidden Horse (& Other Animal) Tricks
Shadow of the Colossus - Sword of Dormin Secret - IGN
Shadow of the Colossus Enlightenments: How to get the Sword of Dormin after finding all 79 coins
Shadow of the Colossus (PS4): How To Find The Secret Garden & Poison Fruit - Gameranx
Shadow of the Colossus (PS4): Hidden Horse (& Other Animal) Tricks
Shadow of the Colossus - All 79 Relic (Coin) Locations, Secret Underground Area and Sword of Dormin
Shadow of the Colossus Sword of Dormin – Gold Coin Mystery Solved - PlayStation Universe
Shadow of the Colossus (PS4): How To Find The Secret Last Guardian Easter Egg Cave - Gameranx
Shadow of the Colossus (PS4): Find 79 New Gold Relics & Unlock The Dormin Sword - Gameranx
Shadow of the Colossus - All 79 Relic (Coin) Locations, Secret Underground Area and Sword of Dormin
Shadow of the Colossus SECRET SOLVED, 79 Gold Coin Relics & THE SWORD OF DORMIN!!!!! (Live Reveal)
Shadow of the Colossus - Sword of Dormin Secret - IGN
Shadow of the Colossus (PS4): How To Find The Secret Last Guardian Easter Egg Cave - Gameranx
Shadow of the Colossus (PS4): How To Find The Secret Garden & Poison Fruit - Gameranx