"World of Goo" is a reference to Kyle Gabler's previous game World of Goo.
World of Goo is a game about building structures out of living blobs of Goo.
World of Goo also had an iconic frog named Fisty, and one level involved building a Goo Ball tongue out of his mouth.
Are there any Goo Balls in any catalog?
Is there a game with a grey frog in any of the catalogs?