The theme behind the Twin Moons being only Luna=Luna could be that despite being alone planet-wise, the two moons are always together. They serve as the bottom grouping for the sixth groupings of Star Trip's Multi mode. The mission of this grouping is "Win within 1:30!," which will let the player go to the middle Meteo if the mission is completed successfully, or the player may choose to go to (or is forced to if the mission is failed) the bottom Meteo.
Molten Hellions | Chlorophylls
Stray Planet | Mechatropoloids | Earth Lovers
Bubblies | Dimensionals
Electric Nymphs | Hot & Chillies | Clean Air Club
Twin Moons | Illusionists | Rare Cultures
Meteo | Hevendor Realm