It took me some time to understand what I was supposed to do in the game, but, once I did, I managed to rack up coins very quickly. It was a fun game. I think I got an Abra (later evolved into Alakazam) and another Pokémon this way.
It was removed from the newer games because a large reason to play it was the TMs, and the TMs became infinite.
I sucked at the slots so Voltorb Flip was a welcome change to me. They should've had more games, though, for example a high-risk/high-reward one, and a low-risk/low-reward one, to make things more diversified.