Yeah, I had to rush the game onto Itch and didn't have time to test it first so I forgot to put the sounds on the later enemies (It only takes like two seconds to add the sounds as well 😓).
I'm thankful that the game only has minor issues though and I'll update it shortly after the jam ends to fix all the bugs and add a few more waves. The "Hard mode" is a good idea as well so I might add that as an option.
Thank you for your input, feedback, and playing my lil' game. 🙂