Reaching for a game of similar influence as Dark Souls, I’m thinking of Zelda. Zelda was a synthesis of smaller innovations with no genre-defining essence, and every succeeding game appropriated different aspects of it. Instead of defining a genre it reshaped everyone’s expectations about what a game can and should be. Prior to Zelda games were either bite-sized arcade action experiences or plodding huge RPGs. Zelda took influences from both and defined a new way of playing (the console game as a whole, really). Zelda, like Dark Souls, established a new overall structure, a new flow of pacing, new types of satisfactions, cognitive engagements and emotional beats.
It’s interesting to compare Zelda to Nazo no Murasame-Jou. The latter has a very similar top-down perspective with room transitions, but it’s linear, much faster paced, and resets all progress whenever you die. Murasame-Jou was a very well-executed game in the arcade tradition that remained obscure, whereas Zelda took basically the same game engine and created a startling new synthesis. Interestingly both Zelda and Dark Souls felt the need to greatly slow down the pace of their parent action genre.