This might look like an empty aquarium to the untrained eye, but in reality this is the best game ever made. It's endlessly fun and frustrating. When was the last time I played it? Maybe twenty five years ago, but I'm pretty sure I'm right about it being fun. The object would be to press the little button which would cause an airflow that launched the rings through the water. You'd want to try and get the rings on the little spikes, which was incredibly difficult. There wasn't even a way to cheat either. Trying to flip it upside down made it just as hard.
I remember seeing these all over the place. Every household had one. There were even special edition versions that had different characters on them. A very popular one was the Teenage Mutant Ninja Turtles version.