Does anybody else have problems hitting Swoopies in Swoopy Salvo? I certainly do. I can very rarely defeat one with an egg. About 95% of the time, the egg just phases the Swoopy, and I get hit because of it. I have to hit right on the beak to defeat it. That means I have to aim from high up, and of course this is annoying because you have to go back down to go into the crevices of trees that the Swoopies are guarding. This is especially annoying in the first bonus, as I've never been able to get to that bonus without taking a hit. Here's a slow motion animated GIF for your pleasure:
I don't have this problem in the GBA version, though. And if this means anything, I'm using the North American SNES version here.