I thought this was just okay. My biggest problem was that it was just too long. You didn't need more for this joke. I don't think fishy Heaven would be being eaten. Then again, I don't know much about fish theology. The animation was just subpar.
I admit that it was kind of an interesting idea. Aren't all fish full of mercury? I named my fish "Fishy"! The voices were alright. It's just nothing memorable.