The first set in the Grand Rush series introduces two new mechanics to Pokémon Ga-Olé: Double Rush (Japanese: ダブルラッシュ) and Rush Combo (Japanese: ラッシュコンボ). Pokémon with the Double Rush icon () have two moves and can use them consecutively when they attack. Reaching the end of the Attack Gauge with one of these Pokémon will trigger Double Rush Chance! (Japanese: ダブルラッシュチャンス！), which presents the player with a roulette wheel consisting of fail spaces and Double Rush spaces. Successfully selecting a Double Rush space will move onto the next phase, which requires players to press the console buttons in effort to fill the semicircular gauges for each move. The blue button will fill the quota for the Pokémon's first move while the orange button will fill the quota for its additional move. When both are complete, the Pokémon will attack twice in succession. Grade 5 Legendary PokémonMewtwo, Mew, Solgaleo, and Lunala available to capture on two of the launch courses all have the ability to perform Double Rush. Legendary beastsEntei, Raikou, and Suicune, which could be encountered on a course from mid-July, as well as the Tower duoLugia and Ho-Oh, which could be encountered on a course from mid-August, can also perform Double Rush. As with the Ultra Legend series, Ultra Beasts could be encountered on courses with an Ultra Beast Appears! icon. From August 1, 2019, players would have the opportunity to capture Buzzwole and Pheromosa, each of which can also perform Double Rush.
Pokémon that have the Rush Combo icon () can perform a combo attack with Pokémon displayed on the disk image. Reaching the end of the Attack Gauge with one of these Pokémon may trigger Rush Combo Chance! (Japanese: ラッシュコンボチャンス！), which presents the player with a roulette wheel for each Pokémon. Using the corresponding console buttons, selecting a non-fail space on both roulettes in a timely manner will allow the two Pokémon to attack in succession. The final forms of the Generation IstartersVenusaur, Charizard, and Blastoise can all Rush Combo with each other as can Generation I EeveelutionsVaporeon, Jolteon, and Flareon. Drill Pokémon Nidoqueen and Nidoking can also Rush Combo together as can the comparable Pinsir and Heracross.
As with previous debut sets of a new series, all Pokémon Ga-Olé machines upgraded to run Grand Rush feature updated UI graphics and have the facility to produce and dispense disks featuring the updated Grand Rush layout. The series also begins a new numbering system—the collection number reverts to 1 but is prefixed with "GR". This set features a number of Pokémon Ga-Olé debuts, including the aforementioned Nidoran lines, as well as the evolutionary families of Phanpy, Togepi, Pidgey, and the regular form of Vulpix. A new version of the Meltan originally from the fourth Ultra Legend set could also be encountered in the Let's Begin Ga-Olé! Course. While identical in terms of stats, it differs by featuring the Grand Rush series graphical layout and a hollow star next to its original collection number. If evolved into a Grade 4 Melmetal, this disk also features the Grand Rush series graphical layout. The Grade 5 version of Melmetal is no different to its Ultra Legend series counterpart.
Trainer and Battle Mode was available to challenge from August 8, 2019 and provided a new roster of opponents to battle. The lineup included two new Trainers classes and a new Battle Leader, Yarma, who could not be challenged until the preceding four Trainers had been defeated. Promotional Reshiram or Zekrom disks could be dispensed for an additional ¥100 following a battle with Yarma, with 'WINNER' versions available to those who successfully defeated his team.
Electivire and Magmortar were added as Support Pokémon from this set. Players registering a Ga-Olé Pass for the first time would automatically receive Magmortar as a Support Pokémon as part of the Pokémon Ga-Olé Welcome Campaign.
Mewtwo Strikes Back Course
Playable at set launch
Solgaleo & Lunala Double Rush Course
Playable from set launch to August 14, 2019
Let's Begin Ga-Olé! Course
Playable at set launch
Raikou, Entei & Suicune Double Rush Course
Playable from July 18, 2019
Powerful Pokémon One After Another Course
Playable from August 1, 2019
Lugia & Ho-Oh Double Rush Course
Playable from August 15, 2019
Available for Pokémon Ga-Olé Members to redeem from July 4, 2019 for 1,000 Member Points
Get It! Mega Latias & Mega Latios Course
Playable from July 4 to November 31, 2019
Available as an insert in the September 2019 issue of CoroCoro Ichiban!, released on July 20, 2019
Its Z-Move! Black Kyurem & White Kyurem Course
Playable from July 20 to September 11, 2019
Special Lugia & Ho-Oh Double Rush Course
Playable from August 15 to September 11, 2019 on select units