Dragon Marked For Death does not have an official "free download" for the full game. It is a paid 2D side-scrolling action RPG available on several platforms. The version you mentioned, (often referred to as 3.1.5s in some regional contexts), was a specific update released around November 2020 that added system changes like "Fatigued State" information and various bug fixes. Official Purchase Options
You can purchase the game through official digital storefronts: Dragon Marked For Death Free Download (v3.1.5s ...
Dragon Marked for Death: Frontline Fighters for Nintendo Switch Dragon Marked For Death does not have an