Bust-A-Move '99

Extra levels:
Press B, Left, Right, B at the title screen. Select arcade mode, then choose the new "Another World" option. Alternatively, press B, C-Left, C-Right, B at the title screen.

Play as Monkey:
Win seven straight in the Win Contest, then defeat Monkey.

Play as Dragoon:
Win with an undefeated record in Vs COM mode under the normal difficulty setting.

Play as Gnome 1:
Win with an undefeated record in Vs COM mode under the hard difficulty setting.

Play as Furby:
Defeat Monkey, then get an undefeated record in the Play Win Contest.

Play as Gnome 2:
Defeat Furby, then get an undefeated record in the Play Win Contest.