While it lacks the Ricoh 2A03 sound chip of the NES, the Gameboy can actually do a pretty decent job of emulating the sound heard on an NES, as demonstrated in this piece from Metroid II. In particular, its sawtooth waves (especially prominent as panning notes in the beginning) are right out of Rygar or Clash at Demonhead on the NES, and the low-buzz bass throughout the entire track is eerily like the dedicated bass channel of the NES. Nintendo-developed games were the best at squeezing out that classic NES sound, which I guess makes sense considering it was their hardware and all.
Metroid Prime 3: Corruption | Bryyo
Metroid Prime III: Corruption - Bryyo Cliffside HD
I’m too lazy to name all the rooms (my apologizes!) I will
Metroid Prime III: Corrupted - Bryyo HD I