As with all Pokémon games, the key aspect here is the capture of Pokémon. To activate the Catch 'Em Mode, you need to go through the table anti-clockwise through the far-right opening three times. Once it lights up the word "GET", you can send your ball into the Bellsprout in the Red Table, or Cloyster in the Blue Table to activate the special Catch 'Em Mode. Alternatively, this mode can open up through a slot bonus
Depending on the area you enter, you will get a Pokémon to capture at random. These are all dependant upon the area you're within so if you're hunting for certain Pokémon, it's best to not leave the area.
When the mode starts, you will get a silhouette of the Pokémon you have to capture. You are given two minutes in order to capture the Pokémon. To get to the actual capture, you need to hit the bumpers at the top of the stage, Voltorb in Red and Shellder in Blue, six times in order to access the Pokémon
Once all six pieces of the silhouette get revealed, the actual capture mode begins. Here, you have to hit the Pokémon three times to uncover the word "CATCH!", earning 3,000,000 points a piece. Finally, hit it one more time and the Pokémon is captured, and stored upon your person for the rest of the session. If it has yet to have been captured, it is now catalogued in the game's Pokédex.