there is a digetically intended whooshing sound when the fire comes up on the screen, the flames symbolize the gunpowder treason and a pheonix rising from the ashes. they were created using cgi and done so cleanly.
it uses a wide angle shot in the scene with the crowd to show the whole scene. parallel editing is used to create a sense of relationship between the 2 main characters. fast takes are used to create a sense of action in the scene. continuity editing is used to create a sense of realism in the film.
it opens with a poetic voice over that describes the gunpowder plot as a beautiful thing which sets up the romantic ideal. the cross cutting of v and evey is done through the tv soundbridge.
the budget for this film was $54,000,000, it was produced by silver pictures, warner bros is the copy right holder, it was filmed in london, it was produced by the same people as the matrix.