Thank you for such a long and detailed feedback!
I didn't notice the diagonal movement bug until now, it shouldn't mean it lands faster cuz it uses coroutine with set amount of time for diepound mechanic. I noticed that it jumps slightly further than indicated range, and it doesn't only happen on diagonals. I should patch that, thanks for reporting the issue. Also I didn't know about normalize() until now, would learn about that later
The tunnel vision issue is maybe caused by all enemies having same bullet sprite, I wasn't sure about that problem but guess it's necessary to fix.
Lastly thank you for your compliments, it's nice to hear that :)