Location
To play "Voltrob Flip," you must first reach Goldenrod City. The game corner is in the southern part of the city. Enter the game corner and talk to the attendant to receive a coin case. Without the coin case, you cannot play "Voltorb Flip." You can now use coins you have purchased or won to play the game. There is a maximum limit of 50,000 coins that you can carry in your coin case.
Playing Voltorb Flip
The goal of the game is to flip over all of that cards on the 5-by-5 grid that do not contain a Voltorb. Any other card will contain a one, a two or a three and will multiply your winnings by that number. Because of this, the twos and threes are the most important number. If you flip over a Voltorb, you will lose all of your winnings. Thankfully, the images on the sides of the grid provide information regarding that specific row or column: the number next to the Voltorb image indicates how many Voltorbs there are on that line, whereas the number above the Voltorb indicates the total value of the numbers added up on that line.
Strategy
The key to winning at "Voltorb Flip" is in the numbers on the side of the grid. If a row or column has a zero next to the Voltorb image, that entire row or column is safe to flip over because it contains zero Voltorbs. Additionally, if the number above the Voltorb and the number of Voltorbs adds up to five, you can safely ignore that entire row, as the ones aren't as important as the twos or threes. If you flip over all the twos and threes without flipping over any of the ones, you still advance to the next stage. Using the numbers, you can make an educated guess as to where the Voltorbs are and safely ignore them.
Cheats
If you find that you keep losing all of your money at "Voltorb Flip," you can input the code "94000130 fcff0000, 62111880 00000000, b2111880 00000000, 00000088 000f423f, d2000000 00000000" using an Action Replay device to purchase the maximum number of coins without losing any money. This will allow you to play "Voltorb Flip" for as long as you want.