This was a really cool concept!! The idea of saving as many patients' lives as possible within a given timeframe kept me on my toes. It's fast-paced and engaging once you get the hang of the controls.
One thing that may help would be to add more UI/HUD elements to help guide first-time players throughout the gameplay - like a quick indicator or "How To" section on how to save the patient's lives and use the medicine/pill cabinet. The medicine/pill (mini-game?) was a bit confusing for me, and I couldn't quite figure out how to work it or exit it, which left me stuck while the patients were piling up. On the 2nd run, I focused on the patient-saving mechanic and really started to enjoy hitting the heartbeat timing. It was satisfying once I got the rhythm of it.
Overall, this game has a lot of potential! Some more clarity on the controls, especially with the medicine/upgrades, would really make it stronger. Awesome job! :)