Dr. Mario is a falling block tile-matching video game[8] in which Mario assumes the role of a doctor, tossing two-colored medical capsules into a medicine bottle representing the playing field. This area is populated by viruses of three colors — red, yellow, and blue — which stay in their starting position until removed. In a manner and style considered similar to Tetris,[9] the player manipulates each capsule as it vertically falls one unit of space at a time, able to move it left or right and rotate it 90 degrees clockwise or counter-clockwise. When four or more capsule halves or viruses of matching color are aligned in vertical or horizontal configurations, they are removed from play. Any remaining capsule halves or whole capsules which are not supported by a virus or capsule will fall to the bottom of the playing field or until it hits another supported object, and any new 4-in-a-row alignments created from this will also be removed. The main objective is to complete levels, which is accomplished by eliminating all viruses from the playing field. A game over occurs if capsules fill up the playing field in a way that obstructs the bottle's narrow neck. After each 5th level is completed on Medium or High difficulty, up to level 20, a cut-scene is shown where the virus trio is sitting on a tree as music plays and an object flies across the screen.[10]
Players are first brought to the options screen, where the starting level, game speed, and music can be chosen. The initial level chosen is a value between zero and twenty that determines the number of viruses to clear, and the three-game speed options change how fast the capsules fall within the bottle. The player's score is based on the elimination of viruses and the chosen game speed, with bonus points for clearing more than 1 in a single line. After level 20 play can be extended to accumulate points, but the number of viruses to clear remains the same.[10]
Dr. Mario offers a multiplayer gaming mode in which two players compete against each other in separate playing fields. In this mode, the player's goal is to clear their own playing field of viruses before the other player does. Eliminating multiple viruses or initiating chain reactions can cause additional capsules to fall onto the opponent's playing field. A player wins a single game upon eliminating all the viruses or if the other playing field fills up. The first player to win three games wins overall.
