Yeah, I recognized my sprite compression code there. Nice thing about that is I can just open a blank cart and replace sset with pset to see the raw sprite data. Beyond that, though, really nice use of color variation, particles, screen distortion, and lighting!
As for suggestions, I just wonder if you'd consider letting the player either eat fish the same size as them, or just pass through them unharmed. It was a bit surprising to find that touching the same size fish kills you.