This article has a talk page!This page details bugs of Higemaru Makaijima: Nanatsu no Shima Daibouken (NES).
The Ever-Pulsating Heart#
The pulsating heart sound effect (ID $24) in Dokuro Island does not stop unless it is interrupted by another sound, but most of the game's sounds have a priority too low to interrupt it (it has the maximum priority). This usually isn't noticed since there is a warp near the heart and the warp sound can interrupt it, but if a player opted not to take the warp and instead backtrack through the island to reach the entrance, the sound will keep playing - even when the game is paused!
Changing PRG-ROM address $273E to $E0 will let the pause sound override the pulsating heart's sound.