Ninja Gaiden III is available on the Nintendo Wii U Virtual Console.
In the Japanese version, a message saying "TO BE CONTINUED NINJA RYUKENDEN-II" appears after 18 minutes have passed at "The End" screen. This is because this game is actually an interquel set between the events of the first and second games and the story continues with Ninja Gaiden II. This chronology of events was downplayed in the US version (the English manual only makes a vague statement about "Ashtar (returning) to the bowels of darkness" after Ryu's duel with Jaquio, which is the only hint that Ninja Gaiden III is set before II, since Ashtar is killed off during the events of the second game (along with the fact that Ryu still possesses the Dragon Sword in the third game despite having lost it in the end of the second). This text was removed in the US version, but it can be restored with the Game Genie code AENLSVNY.
The Japanese version contains a password feature that was removed from the US version. The Game Over screen shows the number of continues left instead of the password the player would have gotten.
The game was made drastically harder for the US version: *Damage taken by the player from most sources is higher: all enemies that dealt 1 damage in the JP version deal 2 in the US version, and all enemies that dealt 2 damage deal 3. Likewise, hazards such as spikes and electric fences, which dealt 3 damage in the JP version, deal 6 damage in the US version. Enemies that dealt 3 damage remain unchanged. *Enemies have been rearranged in every stage, generally being harder to avoid. *The quicksand in Act 2-1 hurts Ryu when he's sunk from the waist down. *Sub-acts no longer have checkpoints for each letter-separated section, causing the player to go back to the start of the entire sub-act if they die. For example, in Act 2-2, which is split into sections from A to D, dying in Act 2-2D or 2-3A (the boss room) sends the player back to the start of Act 2-2D in the JP version, and the start of Act 2-2A in the US version. *The player can only continue up to 5 times after getting a Game Over, being forced to start the game from the beginning if they run out of continues. However, a cheat code has been implemented that gives the player 99 continues if they let the title screen play out 8 times, then hold '''Left''', '''Up''', '''A''', '''B''', and '''Select''' when pressing '''Start'''. *After using a continue, the player starts from the beginning of the entire act, rather than the current sub-act. Using the previous example, getting a Game Over anywhere in Act 2-2 has the player continue from Act 2-2A in the JP version, and Act 2-1 in the US version.