The breathing minigame was supposed to be easy but I do agree that it lowers your heart rate too much. You were also supposed to hear your heart rate during the minigames making the breathing game a waay more relaxing experience and the "panic" one a tenser situation (but sadly I broke that on the last hours and didn't have time to fix it).
The dialogue working with space was just to give the theme and your heart rate (it changes the selection based on your heart rate) more importance. But I'll agree that in its current state it's more frustrating than anything. Thanks for playing and leaving a comment! :)