That bass propels the song along with vigor, and, I'm sure deliberately, the bounce of the tone certainly evokes the titular rubber balls. Like a dance hoedown is a an abstractly surreal alternate dimension! Very fun!

Love the short three lines and the huuba huuba buildup background vocal.

Prior to experiencing this cornucopia of pyschedelia I was just thinking of getting out the melodica.

This is so cool. It makes me think of someone bouncing many balls in a juggling fashion. I get a feeling of tense energy. I like it!

and there was i thinking you always did :-) i think i had a ball like that! banging bass!

The bass is super cool! Keeps the lyrics bouncing throughout the song. That's how I write most lyrics. I used to write lyrics first, identify the rhyme scheme, count the syllables, ad nauseum. But I couldn't come up with music that worked. So, for me, it's best to create the music first and fit the lyrics in as I go.

This sounds playful! Like the bass, the guitar and the melodica play with each other and you are commenting their game!
The whole song has a joyfull rubber ball feeling!