Grassy Plains is the first world in New Super Mario Bros. 3 (3DS). It's a grassy world, it's also very easy. It has nine level eight on the main path and one as a secret level. The Yellow Switch Palace is in this world. Larry Koopa rules this world. Boom Boom guards the secret level.
Grassy Plains 1
The first level in the game. It starts out in a field with Goombas and Koopas. After the checkpoint, it goes into a small forest with Piranha Plants. At the end of the level, there will be a P-Switch that'll have a lot of coins, Cheep Cheeps will also be at the end.
Grassy Plains 2
This level will be underground. It starts out in a field with a pipe in the middle. The level will continue underground with Koopa Troopas, a lot of Brick Blocks and Piranha Plants.
This will take you to the secret stage. At the end of the level, there will be a pipe above three layes of Brick Blocks. Bash them and there will be some Invisable Blocks. Hit them to make to the secret exit.
Grassy Plains 3
A level in the forest. Yoshi will also be in this also. It'll have Monty Moles and Venus Fire Traps. At the end of the level, two Hammer Bros. will guard.
Yellow Switch Palace
The first Switch Palace in the game this will act like the Switch Palace in SMW.
The first tower in the game. The level will introduce Dry Bones and gears. The boss is Larry Koopa, who would act just like him in NSMBW.
Grassy Plains 4
Grassy Plains 5
Grassy Plains 6
Larry's Castle #1
The first castle in the game. Poodoos, Thwomps, Dry Bone and Hammer Bros. will be in this level. Larry will have a rematch with you. He will chuck hammers, and jumps and causes three Goombas to the floor.