Love the cascade effect, but the controls should be more intuitive. The game needs a lot of polishing and bug fixing.
About the use of limitation, i think it would also be a good idea to just add a spear limit. But that would fit in a different game, for example, throwing the spear from the top so it falls and may catch more than 1 fish.
Good job and keep working hard, you may create a masterpiece some day!