Dr. Mario , released on April 30th, 1991 for the Game Boy, is a puzzle game where you play as Dr. Mario, who must drop differently coloured pills onto viruses to remove them from the bottle. Each pill is split into two, with each side being of one of three different colours: red, blue, or yellow. Align three pills of the same colour to a virus of the corresponding colour (or any combination of pills and viruses totaling four or more) and it will be removed from the bottle, along with the aligned pills.
The game features normal mode, time trial, and two-player battle mode, allowing you to compete against others to remove the most viruses. The goal is to clear the level by removing all viruses, but the game ends when the pills reach the top and Dr. Mario can't drop any more pills.