That would be too easy
. It looks like Sappy is the typical GBA sound format (sdat is for NDS).
I tried a few tools like this
. They are all extractors for the Sappy, I think. None of them found anything.
I never noted this anywhere, but WarioWare, WarioWare: Twisted!, and Rhythm Tengoku use similar/identical fonts. Twisted and Tengoku come from the same developer so I think there may even be a similar game engine between the two. (Tengoku was made by a small team on a small budget.) For what it's worth, WarioWare doesn't seem to have Sappy audio either.