The "Super Fat Mario" games, also known as "Super Sized Mario Bros.," involves pressing the left and right arrows to move a morbidly obese version of the Nintendo character Mario across the game field. Pressing the up arrow on the keypad causes Mario to move slightly upwards, simulating a jump.
The "Super Fat Mario" games are meant to be a parody of the popular "Super Mario" Nintendo franchise. The games consist of characters based on those in the actual games, but drawn to reflect a massive weight gain compared to the actual versions. For example, the Mario character has the same trademark overalls, hat and mustache, but is considerably larger in size. The sprite features numerous rolls of excessive excess body fat, meant to mock the diminutive stature of the original character.
The overall gameplay in each game features a heavy influence from the "overweight Mario" theme. For example, pressing the arrow keys to move Mario results in a slow progression across each level. Pressing the up arrow also doesn't cause Mario to jump as he does in other games, but simply shift upwards because his weight prevents him from jumping. When Mario touches an element of the game, such as a pipe, block or enemy, he simply destroys it rather than needing to jump on or over it.