StarTropics is played from a 2D, top-down perspective, similar to many other role-playing games of that era. The game is divided into several chapters; in each chapter, players take control of the protagonist, "Mike," exploring various settlements and other areas of interest and interacting with non-player characters in order to obtain more information about the surroundings. The player is then usually tasked with locating the source of some local calamity or disturbance. When the player enters a more dangerous locale, the game switches mechanics, bringing the view closer in and introducing various obstacles and adversaries that the player must either navigate or destroy.[citation needed]
A yo-yo serves as Mike's primary weapon (renamed "star" in the Virtual Console release[7]). As the player progresses, other weapons and tools are made available that will aid in Mike's journey, including several items influenced by American baseball.
The game was also packaged with a physical letter, which set up the story and was used within the game's plot. During gameplay, the player is prompted to dip this physical letter in water to reveal a hidden code (747), which is required to progress in the game.[8] In response to questions from fans, the code was also published in Nintendo Power.[9] In the Wii Virtual Console release, the letter was added to the manual, which instead plays an animation of the letter being dipped in water before revealing the code.[10] The Wii U Virtual Console release replaced this with an explanation in the manual that the original release required players to dip an insert-letter in water, followed by an image of the submerged letter. However, the Nintendo Switch release does not include any digital alternative to the letter, and thus does not provide any legitimate way for a player to complete the puzzle.[11]