Keep patients alive on the seventh beat
Rhythm Doctor puts you in a hospital where defibrillation works as healing. Your one job is to hit the spacebar in time with each patient's heartbeat, specifically on the 7th beat. Miss the timing and the patient's condition worsens; nail it and they pull through. Each patient comes with a different illness built from real music theory concepts like polyrhythms, hemiolas, and irregular time signatures. You do not need to know those terms beforehand. The levels are built so you pick them up as you go, without sitting down to study anything.
Play the campaign with a friend
The whole story campaign supports drop-in, drop-out local multiplayer, so a second player can join or leave at any point without restarting. You can also play it solo if your group prefers taking turns. For playing together over the internet, Remote Play Together is available, though the developers note that online 2P through Remote Play does not work that well right now because of varying latency between players. Local 2P is the reliable option.
What to know before you start
There are 20+ handmade levels, each with its own story, and a large cast of doctors and patients carrying an overarching character-driven plot. Every level introduces a different rhythm concept in an accessible way, so the difficulty curve teaches rather than gates. For players who want more, each level has a harder "Night Shift" version. There is also a level editor where you can build, share, and play community levels, snap notes to the beat of your own music, and apply 50+ visual effects and backgrounds. One warning worth reading: the game features flashing lights and colors, so use caution if you have experience with epilepsy or any of its symptoms.