Well, there actually are impact sounds - buuuuuuut you kinda need to be listening very carefully for them 😅 (they are kinda quiet and do end up getting drowned out by everything else), so honestly very valid criticism.
I’d say that surviving wave 8 is a very respectable high score. My own high score is 15 (ultimately getting defeated by wave 16), but then again I have the advantage of knowing how badly I bodged together the gameplay (there are exploits I am too afraid to fix for fear of breaking the bot AI again)