I'm glad you enjoyed the game!!
Yeah, the space boundary for the fish is a little ways off the screen. The idea was to kind of invert the player-vibe where every other level before you encircled the fish, but now you don't, so you might not be able to get everything. However without a clear explanation of being able to end the day early, or any guide to explain that I do think it was a mis-step on my part. Thank you for the feedback!