also used to start Chex Quest. Despite Chex Quest's major changes from its predecessor, there are still a few remaining relics (e.g. levels from other Ultimate Doom episodes and some in-game text). While Doom has a cheat code scheme in which every cheat starts with "id", the codes in Chex Quest are based on the names of the people in the production crew of the game, with a few exceptions. PC speaker sound effects from the MS-DOS version of Doom have been modified and are used in Chex Quest. Whereas Doom is rated M for Mature, Chex Quest was made to be a child-friendly game for all audiences. Nearly all of the graphics and audio from Doom have been replaced, from textures to enemies to weapons. Leftover levels Chex Quest has only the first five levels from The Ultimate Doom converted for the game. Some leftover levels are playable (as Chex Quest conversions) only via the level warp parameter at startup. These leftover levels include maps 6 through 9 from episode 1 as well as all maps in episodes 2, 3, and 4. In these levels the music reverts to the original score from Ultimate Doom. After the level warp parameter is used to access maps E3M1 or E4M1, the remainder of the levels (through map 5) within the episode selected can be accessed by completing the levels in the episode in order (just as with the standard level progression in Doom or Chex Quest). Unfortunately, bugs prevent any of the other levels from launching upon completion of the level before it, and similarly E4M9 cannot be reached from E4M2 as previously. Completion of E2M5 (via either exit) displays the end graphic originally displayed at the end of The Shores Of Hell, the second episode of the original Doom, and completing E3M5 displays the end sequence from Inferno, the third episode. Likewise, completing E4M5 displays the end graphic from Thy Flesh Consumed, the fourth and final episode of The Ultimate Doom. Both of the latter two end sequences feature a decapitated rabbit named Daisy. Episode intermission texts which originally (i.e. in Doom) were displayed upon completion of E1M8, E2M8, E3M8, and E4M8 are now found in modified form for Chex Quest. Thus completion of E1M5 in Chex Quest now displays the new message: "MISSION ACCOMPLISHED. ARE YOU PREPARED FOR THE NEXT MISSION? PRESS THE ESCAPE KEY TO CONTINUE..." Completion of