Well the fact that the fish started taking more and more space in the screen (as opposed to having the screen zoom out for example) gave a feeling of being trapped, in a way. But it's not necessarily a bad thing, it can be an aesthetic choice. It didn't interfere in the completion of the minigame. Of course if that's not the effect you were going for then yeah maybe look into it XD
Thank you so much for the further explanation! I intentionally choose to make that effect, and I am quite happy that you feel being trapped. LOL. I am super thankful and inspired of your comparison about the two possible solutions ( fixed camera and zoom-out camera). The zoom-out solution might also be very interesting for an alternative scene in which player has an infinite game play!