Ha, I remember that game. I am a child of the 80's and my friend had Kid Chameleon. It is a good game, I always thought the cover art was kind of odd.
I love retro games. but I really don't like modern games too much. I used to play games to see developers push the envelope on what is possible with low spec hardware. However, most of today's games seem so cookie cutter. Most modern games use prebuilt game engines (unreal and unity), which makes is easy to develop games, but rather boring from a technical standpoint, because all games today use the same core rendering engine. I guess it has lost much of the "magic" for me.
I am trying to think of retro-games that are "fish" related. And the one that stands out is an old/odd game called Seaman, which was first released on the Sega Dreamcast. You play the role of care-taker of a human/fish/amphibian hybrid. It was super advanced for its time: had interesting AI, and perhaps the first home game to ever use microphone based voice commands. It is a someone creepy game as the AI that controls the fish can get a little spicy and rude. I think it once told me off with quite precision.
On the weekends, I sometimes enjoy making retro style games using old tech. None of my games are very good. But I am playing with the idea of making a fish related game at some point in the future.