Riverview Park in Des Moines has a really fun amusement park themed playground. It's quite large with a separate little kid area, which I don't have any photos of because it was crowded during our visit today.
Play Structures: Ages 2-5 & Ages 5-12 (separate areas)
Surface: rubber, fake grass
Swings: traditional, saucer, friendship (shared) & adaptive
Other: ziplines, merry-go-round, large open field
Restrooms: portable restroom near parking lot & bridge
Parking: large parking lot off Corning Ave.
Trails: paved loop trail & paved trail which leads to McHenry Park on the hill above Riverview Park