In Heart's Medicine’s story, they observe Allison with a grim expression in front of the mirror. She recounts how the epidemic came to her hospital with unhappiness. Allison's experience led her to a state of emptiness. She sat in a chair by the window, staring glumly out into the world. However, the hard times she suffered from had openings— opportunities that she was able to take advantage of. The player can help Allison restart three months prior when they learn about her tragic backstory. This new option provides the player with another chance to influence Allison's life. Many different patient cases present themselves throughout the game. Incorrect care can cause patients to get worse or even death. Treating patients the right way, though, can have positive effects and even cure them. Consequently, this requires plenty of attention as a doctor.

Heart's Medicine's first level reveals the first patients as the player approaches. Information appears immediately after and appears as an image that wants to sit in a chair. To direct Allison's activities, you need to touch the same location as her movement at the same time. Moving through different locations in the game's storyline requires navigation of Allison's activities. When checking the status of some patients, Allison formally begins his work when he returns to the Nursery. Some patients can exit the room immediately after his check, but others require hospital beds so the player can care for them. Some patients require players to move quickly to find nearby items; each patient has a certain patience level. Each patient has a time bar that changes color. When requested, this provides each character with the time remaining to heal them. You must first prioritize the most important patients; once you do so, you can progress through the level. Each patient has their own point system and star rating on the side of the screen. You need to collect as many stars as possible and clear the entire side of the screen to get a perfect grade.

Heart's Medicine reveals many curable diseases. Each affliction presents in one of two forms; moderate or severe. Additionally, new health items appear before the player as they cure each disease. Players can replenish their healing resources by taking a set amount of health periodically. If that number runs out, players must continually add to their supply. Some treatments come with a side effect: high stress levels. One example is the process of treating a wound. The process has its own separate evaluation system that doesn’t rely on the player’s level. During the game, time decreases and hearts need to be earned quickly. Heart boxes appear at the bottom of the screen, and specific bandaging procedures are necessary. In order to complete this task, players need to look at two rectangles that overlap each other. Patients help journeyer Allison as she walks the path toward recovery. Since returning three months ago, players help Allison’s business through a terrible situation the two shared. The doctor can treat patients with different conditions in different ways. There are specific time requirements for each patient that the player must meet quickly and accurately. Items required for maintaining the health of the protagonist will appear in front of them. These elements can be navigated at a high pace and quickly restored. New diseases constantly appear and patients constantly appear. This necessitates players to prioritize the important ones.