Just last week, Nintendo added StarTropics - along with other games and goodies - to the NES Nintendo Switch Online app, presenting the game to an entirely new audience. Unfortunately, these new players are finding themselves unable to complete the game thanks to what can only be described as a bizarre oversight from Nintendo itself.
For those unaware, the game provided players with a neat out-of-game gimmick to enjoy when it launched back in the '90s. The game tells players to dip a letter from Dr. Jones into some water to discover a secret, and this letter was included physically as part of the included manual. Players had to physically dip the paper in water at home to be presented with a three-digit code. You can see it in action below (we wish things like this were still a thing).
The Wii U Virtual Console release, which arrived in 2015 digitally and therefore without a manual, got around this by simply showing the wet version of the letter in the digital manual.
So, what's the problem with the Switch Online version? Well, it doesn't have the Wii U fix included, and instead simply tells players to dip the letter into the water, waiting for the code. Of course, players don't have a physical letter, and there isn't a digital copy available either, so what are they supposed to do? It seems Nintendo simply forgot about the feature entirely.
The video below shows the moment that you're asked for the code. If you happen to have landed on this page after searching for the problem online, the code you need is 747.
It's currently unclear whether or not Nintendo will patch in some sort of change or update to help players out in this scenario, but at least you now know what to do if you come across that part of the game. You couldn't make this stuff up.