StarTropics is an action RPG released by Nintendo specifically for the North American and European markets. Players become 15-year-old hero Mike Jones as he travels to the C-Islands in the South Seas to visit his uncle, the brilliant Dr. Steve Jones, only to find he has been abducted by aliens!
Now Mike must explore the tropical island archipelago in search of his uncle, while defending himself against an otherwordly menace. The game is presented from top-down 2D like traditional JRPGs, complete with a world map of the islands to explore and locales to visit. Mike can interact with NPCs in villages to learn more about his objectives. Battles also unfold from a top-down perspective and are conducted in real-time just like in Nintendo's Legend of Zelda series.
Curiously, the game was never localized in Japanese despite being produced by a Japanese team of developers from Nintendo's inhouse studios.
In a fine nod to the bonus physical "feelies" items which came bundled with classic RPGs, the original physical retail copies of StarTropics similarly included a "letter" from Mike's uncle. More than just an in-game reference however, at a certain point in the game the player was actually required to submerse this real-world letter in water in order to acquire a secret code necessary to progress in the game itself.
This naturally lead to issues where players had no easy access to this actual letter (either through second-hand purchase of the original game cartridge or during a rental), thus being left with no way to progress through that particular portion of the game. Due to the number of inquiries Nintendo of America received from callers as a result, the publisher eventually published the code (7-4-7) for all to see.