Transformers: Convoy no Nazo

Transformers: Convoy no Nazo ("Mystery of Convoy") is a Japan-only Famicom release that is nigh-unplayable. Oddly enough, Convoy (or Optimus Prime, as he's known outside of Japan) does not actually appear in the game.

Unused Music
The title screen music has a little fanfare that is never heard normally, because the game plays a demo just before it. After the first 16 seconds, there is a 4-second pause and then the fanfare plays.

Track #5 of the NSF is a light-hearted tune that doesn't fit very well with the game.

Track #6 was clearly intended for a cutscene.