Blaster Master Trivia (NES)
Japanese versionThe Japanese version differs from other oversea releases in that it doesn't have the intro sequence that explains the whole bit about your frog, radiation and the underground cave. This is because the Japanese version has a completely different story in which the main character is the hero of the planet Sophia and has to fight off an alien invasion (this difference also introduces minor changes to the game's beginning and ending).
Sound effectsMost of the sound effects in Blaster Master were eventually reused for several other SunSoft NES games, the most notorious of which was Fester's Quest which features similar gameplay to Blaster Master's overhead-view sequences.
Information also contributed by Zovni