I really enjoyed starting in the dark and slowly improving: very, very satisfying. I did crave working towards some sort of godmode-type payoff -- this previous submission's improvement curve might be good inspo for you on that front.
I recommend against purposefully making your game's sounds annoying. Just like you adhere to a visual aesthetic, consider adhering to a sonic aesthetic as well. (These two can mesh with each other, or deliberately subvert each other.)
Having thought about it more, I will say the rarer a sound is, the more okay it is for that sound to be deliberately annoying.
Anyway, thanks for sharing!