For many, specifically those playing on legacy hardware or Android, 1.5.6 represents the "perfect" state of the game—a stable, polished diamond before the engine changes of the recent 1.6 update. Searching for this specific version is a nod to the fact that the game’s evolution is so complex that different versions offer vastly different gameplay experiences.
Stardew Valley was famously created by a single solo developer over the course of four years. Even after achieving massive success, ConcernedApe has continued to release monumental content updates—like version 1.5 and the subsequent 1.6 update—completely free of charge for people who own the base game. stardew valley 156 free download link
Unfortunately, I couldn't find a legitimate free download link for Stardew Valley. The game is available for purchase on various platforms, including Steam, GOG, and the Nintendo eShop. For many, specifically those playing on legacy hardware