The Grasslands (S1) is the South entry stage after the Gear elevator from A Town in Chaos. Use the finder below for every Gray, Red, Green, and Blue chest, all eight Musical Coins, and the Wormwould arena—with exact room-map links for Day/Night and each map variant. First priority is the Gray Chest Yellow Music Box, which opens the path to The Big Bridge.
FIRST CLEAR PRIORITY
Open the Gray Chest for the Yellow Music Box, then push to The Big Bridge
Find the Gray Key in room 14, open the Gray Chest in rooms 4 / 13 (same arena as Wormwould), and take the Yellow Music Box. Playing it on the overworld opens the South route from The Grasslands into S2 The Big Bridge. Grab the Red Chest Truck Wheel on the same pass if the Red Key route is free—it unlocks Variant 2 of The Volcano's Base.
S1 CHECKLIST · THE GRASSLANDS
Grasslands Finder
0 / 13 targets marked · browser checklist only
Map links open the Room & Target Index for this level. Match Day/Night and variant to your overworld state. The Gray Chest and Wormwould share rooms 4 / 13. Progress is stored only in this browser and never touches a cartridge, emulator, or Nintendo Switch Online save.
ALL FOUR CHESTS · S1
The Grasslands treasures by chest color
Each chest needs its matching key color in the same level. Colors are not unlocked globally—if you drop a key, go back and pick it up again. Room numbers below match the default Day layout; open the map link for live markers on your current Day/Night and variant.
| Chest | Treasure | Key rooms | Chest room | What it does | Map |
|---|---|---|---|---|---|
| Gray / Grey | Yellow Music Box |
14 | 4, 13 | One of five Music Boxes. Opens the overworld route from The Grasslands to S2 The Big Bridge. | Open Gray Chest map |
| Red |  Truck Wheel |
0, 6, 9, 16, 18, 19, 21, 23 | 5, 24 | Unlocks Variant 2 of W2 The Volcano's Base for later layout routes. | Open Red Chest map |
| Green |  Magic Wand |
1, 2, 20 | 29 | Collectible treasure for the full 100-treasure Perfect clear. | Open Green Chest map |
| Blue |  Fighter Mannequin |
8 | 28 | Collectible treasure for the full 100-treasure Perfect clear. | Open Blue Chest map |
SOUTH ROUTE · GRAY CHEST
Yellow Music Box from The Grasslands
Yellow Music Box
Pick up the Gray Key in room 14, then open the Gray Chest in rooms 4 or 13. Those chest rooms also host the Wormwould boss arena, so the Gray route and boss path share the same destination family.
The Yellow Music Box is one of the five Music Boxes required for the main story clear. Playing it on the overworld opens the path from The Grasslands to S2 The Big Bridge.
Open Gray Chest map → · All Music Boxes guide → · Ending requirements →
Clear the Gray route
Key in room 14, chest in rooms 4 / 13. Beat or pass Wormwould as needed to finish the Gray Chest.
Play the Music Box
Exit to the overworld so the Yellow Music Box event updates the South map.
Enter The Big Bridge
S2 holds Magic Seeds, Cyan Crayon, and more South progression toward the Tower of Revival.
MAP VARIANT · RED CHEST
Truck Wheel and The Volcano's Base
Truck Wheel
Hunt the Red Key in the long ground-room family—rooms 0, 6, 9, 16, 18, 19, 21, and 23—then open the Red Chest in rooms 5 / 24.
The Truck Wheel unlocks Variant 2 of W2 The Volcano's Base. It is not required for the Music Box ending, but it is a real map-changing treasure for later West routes and 100% clean-up.
Open Red Chest map → · Volcano's Base guide → · Map-changing treasures →
BOSS · WORMWOULD
How to beat Wormwould in The Grasslands
Wormwould
The boss arena is indexed in rooms 4 and 13—the same room family as the Gray Chest. Wait for the worm to surface, avoid rolling rocks and palm hazards, hit while the head is exposed, then wait out the underground reset before the next cycle.
Clearing the fight supports the Gray Chest path rather than a separate story gate. If you only need the Yellow Music Box, treat Wormwould as the arena hazard on that Gray route.
MUSICAL COINS · MUSIC COINS
All 8 Musical Coins in The Grasslands
Every level has eight Musical Coins (also called music coins). They are not required for the Perfect treasure screen, but finishing all 200 coins across the game unlocks Golf Building Course 4. Room numbers match the Day layout; all eight coins index on the default Variant 1 map.
| Coin | Primary rooms | Also present in | Notes |
|---|---|---|---|
| Musical Coin 1 | 0 | 6, 9, 16, 18, 19, 21, 23 | Red Key ground-room family |
| Musical Coin 2 | 0 | 6, 9, 16, 18, 19, 21, 23 | Same room family as Coin 1 |
| Musical Coin 3 | 1 | 2, 20 | Green Key room family |
| Musical Coin 4 | 5 | 24 | Near Red Chest rooms |
| Musical Coin 5 | 8 | — | Blue Key room |
| Musical Coin 6 | 14 | — | Gray Key room |
| Musical Coin 7 | 28 | — | Blue Chest room cluster |
| Musical Coin 8 | 28 | — | Same room as Coin 7 |
Open all Musical Coin markers → · Full Musical Coins Finder for every level →
ENEMIES · GRASSLAND HAZARDS
Creatures you will meet in The Grasslands
S1 mixes open field walkers with the Wormwould boss arena. Day and Night can swap connections, so keep the Day or Night Spell handy for clean-up visits.
Wormwould
Boss in rooms 4 / 13 with the Gray Chest
Spearhead
Pointed walker on open grassland routes
Snake
Ground hazard in mid-field rooms
Orange Bird
Air pressure on higher ledges and side paths
MAP VARIANTS · DAY & NIGHT
When The Grasslands layout changes
S1 has four progression variants on both Day and Night. Variant 1 is available once the Gear elevator opens the South map. Later variants open after you collect specific treasures elsewhere:
| Variant | Requirements | Notes | Map |
|---|---|---|---|
| V1 | None | Default first visit. Grab Yellow Music Box and Truck Wheel here. | Open Day map |
| V2 | Magic Seeds (S2 Gray Chest) | Layout revisit after The Big Bridge Magic Seeds. | Open Day map |
| V3 | Flute (E1 Gray Chest) | Later South clean-up layout after The Stagnant Swamp Flute. | Open Day map |
| V4 | High Jump Boots (E4 Green Chest) | High-jump revisit for remaining routes and 100%. | Open Day map |
FIRST VISIT ROUTE
What to do in The Grasslands on a new file
Gray Key → Yellow Music Box
Room 14 for the Gray Key, rooms 4 / 13 for the Gray Chest and Wormwould. Leave with the Yellow Music Box.
Open The Big Bridge
Exit and play the Music Box so S2 unlocks. Grab Truck Wheel if the Red Key family is already on your path.
Revisit for 100%
Come back for Magic Wand, Fighter Mannequin, Musical Coins, and later variants after Magic Seeds, Flute, or High Jump Boots.
FAQ
The Grasslands FAQ
How do I open The Grasslands?
Collect Gear 1 from W3 The Pool of Rain Gray Chest and Gear 2 from W4 A Town in Chaos Gray Chest. Both gears repair the elevator that connects A Town in Chaos to S1 The Grasslands.
Where is the Yellow Music Box?
Gray Chest in The Grasslands. Gray Key is room 14; Gray Chest is rooms 4 and 13, the same arena family as Wormwould. Playing the Music Box opens S2 The Big Bridge.
What does the Truck Wheel do?
The Red Chest holds the Truck Wheel. Collecting it unlocks Variant 2 of W2 The Volcano's Base. It is optional for the main Music Box ending.
How do I beat Wormwould?
Wait for the worm to surface in rooms 4 / 13, avoid rocks and palm hazards, hit the exposed head, then wait out the underground reset. Full form-based tips are on the bosses guide.
Are Magic Wand and Fighter Mannequin required?
No. Both are collectible treasures for the full 100-treasure Perfect screen. The main story clear needs the five Music Boxes, including Yellow from this level.
Does this guide work on Nintendo Switch Online?
Yes. The English Game Boy Color release on Nintendo Switch Online uses the same chest colors, Music Box rules, Wormwould arena, and Musical Coin counts as the original GBC version.