Moon Gems will help your gameplay in various ways including:

- Continuing the game
- Expand item box
- Purchase Spelamin Z
- Purchase "Cake" and "Candy" used for "Doggie Digging"
- To compensate for insufficient gold when entering the "Championship stage" (Beginner: 30MS/Intermediate: 60MS/Advanced: 90MS)
- To enter a "Rare Materials Dig stage" or "Gold Rush stage" when you are missing a "Superalloy Key" or "Golden Key" (100MS for each key)