Im glad the feedback was useful.
* Almost every sound gets cut at some point. Im 100% sure the "bzzth" sound comes from them being cut 'cus i did sound editing myself in the past and it is exactly what you hear if a the sound wave goes back to zero (something like this https://imgur.com/x0i9O1G)
I've never used unity but what i could recommend is that IF you run a "stop sound" command at any point, change it to a quick fadeout (lowering the volume to zero in half a second before stopping it would prevent any "bzzth" effect)
* The chat system could be implemented as a pool of one liners that get chosen at random.
* I know "bigger things" could end up messing the geometry up, but you could add it as an endgame feature (for example once free injections are bought, sort of a "go nuts at your own risk" mode)