 The game included 15 levels, and came in both color and monochrome.The game was released on 6 December 2001, as well as two demos for the color and the monochrome versions of the game.The Xbox edition of "Serious Sam" had notable differences including the model of Sam being changed from the model of "The First Encounter" to form a more cartoon style Sam, removing the shades to make him look less like Duke Nukem and more like he does today.