A vertically scrolling video game or vertical scroller is a video game in which the player views the field of play principally from a top-down perspective, while the background scrolls from the top of the screen to the bottom (or, less often, from the bottom to the top) to create the illusion that the player character is moving in the game world.[1]
Continuous vertical scrolling is designed to suggest the appearance of constant forward motion, such as driving. The game sets a pace for play, and the player must react quickly to the changing environment.