Grassy Greens

From the Super Mario Wiki

Grassy Greens was the first world Mario went to in Mario Pinball Land. As its name implies, the land was covered in grass and possessed a farm-like setting (with the farm tune to boot), along with classic enemies like Goombas and Koopas, beehives with Bumblers, and a big windmill (where Toad's Tent was located nearby). Inside the windmill, Mario fought what would appear to be a deformed version of Petey Piranha and took his Star Key to move on.

[edit] Screenshots

The area with the windmill.

Mario's battle against Petey.