StarTropics has a major issue with the Nintendo Switch Online release, since when the game originally launched on the NES, the game’s instruction manual included a physical letter to Mike from Dr. Jones printed on parchment.
When players dipped the letter into water, it would provide further instructions for Mike with a code that allows players to progress through the fourth chapter.
While a workaround was provided for the Wii U Virtual Console release a few years ago, StarTropics on Nintendo Switch Online has no workaround of its own with nothing in the game itself, or anywhere else in the app itself with instructions. This is something Nintendo needs to address.