Hey :)
The sound effects really help! Personally not sure how the high score system would be different after a short play test.
That does make sense, tho if I click fast I will pretty much always be punished with damage and I can't stay in the flow. If the intent is to make the player click slower, then the health bar would need to drop faster for me to stay engaged. If the difficulty does ramp up a lot more later on, I haven't gotten that far (lvl 5 was my maximum) and by then I would have lost interest in the game with the current amount and variety of mechanics and content.
But for a prototype this makes sense. Will the bigger game have an indication of a bigger pay off or a carrot on a stick mechanic? Let me know when you have more to show :D