Medical 91 is a Japanese-style visual novel. The majority of the game is spent reading and listening to the story unfold, though Yuna will often be given choices that will cause the story to branch in varying ways. At many points, it is possible to move freely throughout the hospital to speak with the other characters on numerous subjects, with the story only proceeding once the proper conversations have taken place. There are also certain segments where the player must choose locations to escape pursuit, as well as avoid capture in a timing-based minigame.

Medical 91 is a Japanese-style visual novel. The majority of the game is spent reading and listening to the story unfold, though Yuna will often be given choices that will cause the story to branch in varying ways. At many points, it is possible to move freely throughout the hospital to speak with the other characters on numerous subjects, with the story only proceeding once the proper conversations have taken place. There are also certain segments where the player must choose locations to escape pursuit, as well as avoid capture in a timing-based minigame.