Mario Bros. is a classic arcade game originally made and released by Nintendo in 1983 and converted to every home console and computer known to man. It was a spin off of from the Donkey Kong series of arcade games, and also heavily influenced by Joust. It was the first game to feature Marios name in the title. Plus It was also the debut of Marios little brother, Luigi. Unlike Donkey Kong where Mario was a carpenter, in this game Mario was promoted to the role of a plumber, but instead of fixing leaks he exterminated pests exiting from pipes.

A remade version of the game is included with the original NES release of Super Mario Bros 3 and in the remake, Super Mario All Stars. Enhanced remakes of Mario Bros. were released on the Famicom Disk System (named Kaettekita Mario Bros.) and with all four games in the Super Mario Advance series and Mario & Luigi - Superstar Saga. It is also available to download on Nintendos Virtual Console.

Mario and/or Luigi must defeat all the enemies coming out of pipes in the corners of the screen. Enemies must first be hit from below to flip them over, then touched to kick them off the screen. However, if an enemy is left upside down for too long, it will flip back over. Coins also come out of the pipes, and they give the player points.

In the sewers of the city, normal animals (turtles, flies, and crabs) have been mutated by the ooze. Two plumbers, The Mario Bros., are working in the sewers when the mutant monsters attack them. The two set out on a journey through the sewers to defeat all the monsters and save the city.