Unlocks Endless for DDR 3rdMIX for PlayStation. Since you can't unlock this game through System Data Support, we have to do this the hard way:
- Set number of stages (MEDIUM) to 5
- Play 140 songs in groups of 5 to unlock HOME2 ending
- Set ending to HOME2 and number of stages (SOFT) to 1, play 1 song to unlock BG Collection
- Play 10 songs to unlock Endless
Incidentally, this also unlocks everything else except the BG Collection backgrounds.