Jam mode (a secret mode) has extra visual effects and background audio clips with no change to gameplay.
dʒˈæm mˈoʊd ɐ sˈiːkɹᵻt mˈoʊd hɐz ˈɛkstɹə vˈɪʒuːəl ɪfˈɛkts ænd bˈækɡɹaʊnd ˈɔːdɪˌoʊ klˈɪps wɪð nˈoʊ tʃˈeɪndʒ tə ɡˈeɪmpleɪ.