From Wikipedia:

   Dr. Mario is a 1990 Mario arcade puzzle game developed by Gunpei Yokoi and produced by Takahiro Harada. Nintendo has developed and released a game for Nintendo Entertainment System and Game Boy consoles. 

The soundtrack to the game was written by Hirokazu Tanaka. 

The game focuses on the character of the player Mario, who takes on the role of a doctor and has to destroy deadly viruses. 

In this puzzle game with falling blocks, the player's goal is to destroy the viruses that fill the playing field on the screen with the help of colored capsules that are dumped in the field. 

The player manipulates the capsules when they fall so that they match the viruses of the appropriate color, which takes them out of the game. 

The player advances through the game, eliminating all viruses on the screen in each level.

   Dr. Mario received a positive response and was included in several lists of the best Nintendo games of all time. The game has been ported, remade, or has been sequels on every Nintendo home console since NES, as well as on most portable consoles, including a 2004 re-release on Game Boy Advance as part of the classic NES series. Modified versions of Dr. Mario have been included as mini-games in WarioWare, Inc.: Mega Microgames! and Brain Age 2: more workouts per minute per day!.

   Dr. Mario is a video game with falling blocks, in which Mario plays the role of a doctor, throwing two-color medical capsules in a drug bottle representing the playing field. This area is home to viruses of three colors: red, yellow, and blue. In a manner and style that are considered to be similar to Tetris, the player manipulates each capsule when it falls, moving it left or right and rotating so that it is located next to viruses and any existing capsules. When four or more halves of capsules or viruses of the same color are aligned in a vertical or horizontal configuration, they are removed from the game. The main goal - to pass the levels, which is achieved by eliminating all viruses from the playing field. The game is over if the capsules fill the playing field so that they close the narrow neck of the bottle.

   Players can choose the degree of starting difficulty any time a new game starts. The initial level chosen is a value from zero to twenty, which determines the number of viruses that need to be cleared, and the three variants of the speed of the game change the rate of drop capsules per bottle. The player's account is based solely on the destruction of viruses, not on the time spent on passing the level or the number of capsules used. If players pass the highest level of difficulty, they can continue the game to score a higher score, but the number of viruses that need to be removed remains the same. Additional points are awarded when multiple viruses are destroyed at the same time, but no additional points are awarded for initiating chain reactions in which the elimination of one set of objects causes the destruction of another set. The speed of the game is also a factor influencing the scoring in the game; The higher the speed, the more points.

   Dr. Mario offers a multiplayer game mode in which two players compete with each other on different playing fields. In this mode, the player's goal is to clear his playing field from viruses before another player does. 

Eliminating multiple viruses or initiating chain reactions can cause additional capsules to hit the opponent's playing field. 

The player wins a single game after all viruses have been destroyed or if another playing field is filled. In general, the player who wins three games first wins the winner.

More information about this game can be found on Wikipedia.org.