Honestly, the game is so simple yet so fun that I'm surprised this idea hadn't popped up ever in a 8-bit arcade game when they were still on their peak era. Really fun game!
However, it seems like there's a possibility to play with a second player that I couldn't find. On the pause menu there are the controls but I couldn't find anything that explained how to summon Player 2. Anyway, I'm pretty sure you either have a coop or versus mode for that 2nd player and that would make the game much more replayable.
Great game overall! The frying fish is more original than fishing fish, but still. Anyway it's a cool game based on a concept more original than the average UFO-fishing game.
Nice work!