By following along to the Rhythm of the song and matching your button press to the beat of the song. With each successful tap you revitalize your patient. The better you do, the better the ranking you will receive.
Getting a good ranking will allow you to see more patients (unlocking more songs) and unlock a higher difficulty setting.
Art and Design
Character collapse in pain when your miss notes, or gain energy and glow when you are keeping the beat alive. The animations are expressive, and that helps communicate just how well you are doing.
The game is a little tricky at first, it takes some getting used to and unlike games like Rock Band/Guitar Hero you have to use your inner sense of rhythm and timing.
For example, when I first played the samurai stage, I thought I was doing awesome! The background was going crazy, the ECG line was glowing and the music was pumping. After the song ended I came out with a D rank. What I didn't notice is that there were also words that popped up on the top left of the screen with the usual "Too Early" and "Perfect". They got kind of lost with all the things going on. This is the only real con, but once I knew what was going on I could deal, and this is not a game breaker.
Beats Per Minute