I noticed that sometime I would avoid the red fish, but it would still count as a hit. Maybe the hit-boxes for the red fish are a little too big?
I also experienced the scrolling-page issue with the arrow keys. Frankly I will just blame itch.io for this, and not you. Also this is an easy fix so it isn't too big of a deal.
I like how the text beneath the canvas changes color based on what fish you touch.