Re-doing this section with links to NG audio portal.
I also found a 10-Hour extension.
There should really be a sequel to this game.
Theme Song (Newgrounds Rumble Theme)
https://www.youtube.com/watch?v=l0hY76-XgZ8
Pico's School (Newgrounds Rumble BGM4)
https://www.youtube.com/watch?v=YTeawcMO0mA
Japanese Garden (Newgrounds Rumble BGM2)
https://www.youtube.com/watch?v=k8U51NXl1O0
Meat Locker (Newgrounds Rumble BGM1)
https://www.youtube.com/watch?v=R_YI26VrbB0
Piconjo Manor (Newgrounds Rumble BGM3)
https://www.youtube.com/watch?v=1efsOJCFXmY
The Portal (Newgrounds Rumble BGM5)
https://www.youtube.com/watch?v=BLwt2cqscSM
Which one is your favorite?