Start the game and as the intro plays, it will auto-exit back to the menu and the music will start layering on itself.
Intro should play without exiting to menu.
Game is AS2
I can't reproduce this issue anymore in the latest version of Ruffle.
I checked it out on my end and I can confrm that the game diidn't exit back to the menu during the intro. Though the intro FMV music seems to still continually play in a loop, which gets very noticable as you try to get into the game.