The game design team first established the rules of the gameplay, and the size and abilities of the characters to move and jump around, including what light sources would reflect on them, plus the impact of the puzzles, and then rigorously based the measurements of each room on them. After the illustrators had determined the decoration and lighting ambiance of the rooms, 3D graphic designers modeled each of them in polygons. Finally, "bitmappers", as the Cryo company called them, applied textured surfaces to the walls and objects [Source: official French Cryo Interactive site].