Ripping from Mario Party 4

[Raccoon Sam]

Looking at the files in a hex editor, they all seem to contain the string "HSFV037" many times in many places. This is a likely file header.
Googling "HSFV037", I found a BMS script exists for Mario Party 6 BINs (and 7) and I'm lead to believe the same tool can unpack these BINs so you can get individual HSFV037 files out for closer inspection. Surely enough, using the BMS script spits out a large amount of sub-files from the BINs.

I suspect HSFV037 stands for Hudson Soft File version 037, so existing tools made for Nintendo's in-house model formats won't work here (BMD et al).

tl;dr: Format that needs to be cracked is called HSFV037. Can't help you there, sorry.