Thanks for playing and for leaving such a detailed comment.
I still need to experiment more with sounds but I did recently experiment with having the game say whether a shot was too early or too late after it was suggested to me but because the turret can rotate in either direction and enemies move slower or faster it became a bit confusing. In the end I felt it was clearer to let players judge that from whether the beep happens before or after their shot, along with the new “degrees off” feedback in my update made today which definitely helps. I have changed the language url again too so I'm hoping this time it won't speak in Portuguese.
I really like hearing ideas from other developers even if it could be useful for another game. One of my goals with making games is to inspire others, so suggestions like yours are always appreciated!