Gal Metal originally debuted in Japan last February. A year later, some brand new DLC has been made available. The Additional Tracks Pack can be purchased on the Japanese eShop for 500 yen.
The DLC includes a total of five songs. SHOW & MONOTONE, Ro・Ro・Roma・nce!, Turkish Signal Gun, Sound! The Fourth Dimensional World Song!, and Inokashira Rothbart are featured in the pack.
Since this is “Pack #1”, it’s looking likely that Gal Metal will be receiving additional DLC going forward.