The Classic NES Series is a collection of retro games for the Nintendo Entertainment System (NES) console. It first appeared in the Nintendo Entertainment System (NES) and Game Boy Advance, where it also had a version as Dr. Wario in WarioWare, Inc. The game was rereleased in 2001 as part of a collection titled "NES Classics". This set of games contains Dr. Mario and his friends, as well as Puzzle League.
Dr. Mario was released for the Nintendo Entertainment System and Game Boy in 1991. It is the first game in the "Dr." spin-off series of Super Mario games. It was released in Japan in July 1990 and later in North America and Europe in October and December 1990. The Game Boy version was released first in Europe, followed by the NES version in June 1991. The game is still considered a classic in its own right.