I approached this game with the main ethos: breaking the engine is fun! That feeling where something you built is progressively becoming super powerful over time is an awesome rush, so I'm ecstatic you felt this way!
Re: the menu: THANK YOU! I was so happy with how it turned out, and I'm glad it's resonating with others.
On the audio: Yeah, this was something we really wanted to do but we just ran out of time. We will definitely add this feature though.