I can't start to explain the emotions evoked by this masterpiece, there is so much good stuff all around, you have cool fish, weird fish and somehow even Cthulhu, I'm truly speechless, well done developer, you made a grown man cry.
Glad you enjoyed it. By the way, to reach the ending, you have to sell each fish at least once. When you sell each fish at least one, once you sell Cthulhu, you get the ending cutscene