Although I got past the first guy by sheer blind luck, I struggled on the second guy a bit before I quickly realized what I was supposed to do.
No idea why others are acting like it's such a hard thing to figure out when the clue is literally screaming in your ear.
Although the timing could be a little more lenient.
Edit: Played through it again, turns out I was meant to kill the first guy no matter what. A pretty clever tutorial, I don't think I could've figured out how to win without knowing that the A button does indeed work.
Unfortunately, I still couldn't beat the last guy, and I know he's probably beatable thanks to the secret achievement.
It'll probably remain locked for me, I don't think I have the patience for TAS-level inputs again.
[SPOILERS BELOW]
You need to memorize the amount of "Caw"s it takes before each enemy shoots, then shoot exactly then.