Pictured: The new revamped background of the Excitebike stage!
Those of you who played Melee's adventure mode back in the day might remember the F-Zero section; it was composed of a long road that the player had to run across, all the while avoiding the F-Zero cars that would drive by. The player would be notified of the cars beforehand, since they would run in the background before reaching the foreground.
The same is now true for the Excitebike stage as well. Not only do the bikes in the background provide an extra visual cue for when fighters have to take cover, but the stage overall looks more 3 dimensional and believable.