Hi, congrats on your game! :) Great idea to use a game involving heartbeats. I think it would be interesting to add new types of beats (even if they don't make sense in real life), maybe some puzzles, like a cough sound that quickly increases the heartbeat's speed...
If you have some spare time, please try out my game. It's a classic space shooter from the 80s but with a personal touch. Please leave your honest feedback.