Quiz no Hoshi is a trivia game with several gameplay modes; the main one is called "Heart of Stone" and is a story-driven series of quiz encounters with strategy board game elements. The plot involves a kidnapping of a little girl by the mafia, and the attempts of a boy named Hoshimaru to rescue her, all the while escaping from an impending apocalypse. Hoshimaru can be navigated over a board (often with branching paths); each field usually leads to a conversation scene with a following quiz. Both Hoshimaru and the "enemies" have life bars; the protagonist's health increases after successfully completed quiz challenges. Correct answers damage the enemy, while wrong answers deplete the hero's life. The amount of possible answer to select from and the nature of trivia questions varies from quest to quest.

Other modes include a multiplayer tournament, a time attack mode in which players have to answer as many questions as possible within a time limit, and two multiplayer modes that allows players to represent various characters and mimic a fighting game and a Formula 1 Grand Prix.