This is a comments thread for the following album: https://downloads.khinsider.com/game-soundtracks/album/u.n.-squadron-arcade
It's only used in the Japanese version of the game. The special round occurs randomly at any point after Stage 3, and is a short bonus level where you shoot bombs off of a jet. The Cutting Room Floor's article for the game has more information.So, where does 'Special Round' play at?