Next Piece Indicator
In puzzle games where players must arrange multiple pieces in a restricted space, players benefit from information about upcoming pieces they will have to place. In order to provide such information, some games provide an indicator in their head up display that provides information on upcoming pieces.
Tetris [Pajitnov, 1986] lets players see what shape the next tetrad will be so they can plan their placement strategies. While versions (and derivatives) of Tetris vary, many versions place this indicator to the left of the main play area.
In Bust-a-Move 4 [Taito, 1998], players arrange a set of bubbles, looking to chain together series of three bubbles or more of the same color. To help players plan their strategies, the game provides an indicator on the right side of the play field that displays the color of the next bubble.
Dr. Mario's (Nintendo Remake 1994) next piece indicator is integral to completing the puzzle successfully. Dr. Mario is a fast paced puzzle oriented game that requires the player to line up colored halves of pills with virus balls. A virus ball plus 3 other halves of a pill of the same color will "cure" the virus and make it disappear. Knowing the color of the next pill is necessary to plan strategies and leave less of a mess later in the round.
Pajitnov, A. (1986). Tetris. Dos edition.
Taito, developer. (1998). Bust-a-Move 4. Taito, playstation edition.