Chex Quest

Chex Quest is an award-winning promotional game created by and released in, utilizing the Doom engine. The player is embodied as Chex Warrior, a hero attempting to rescue captured Chex people from evil slime creatures known as Flemoids who have invaded the Intergalactic Federation of Cereals' mining outpost on the planet Bazoik. The game was made available inside boxes of cereal. It featured five levels. Because the market for the cereal consisted largely of children, the game was made to be deliberately non-violent: for example, the enemies in the game are not killed, but are instead transported back to their home dimension.

The game is notable for the fact that it was the first game to be released inside a cereal box. Sales of Chex cereal increased by 295% in incremental volume over base and 48% in volume share during this promotion. Much of the manufacturing cost of the CDs was paid for by. AOL was allowed to include its dial-up online service client on the disc in exchange for this contribution.

Story
Chex Quest begins with an emergency meeting of the members of the Intergalactic Federation of Cereals. In it, it is brought to everyone's attention that a volcano exploded recently on the surface of Bazoik, a peaceful mining planet renowned for its quality nutritional products. The Chex Squadron captured fragments from the explosion, and discovered that they contained strange, slimy larvae of a creature from another dimension. When exposed to nutritional substances, these larvae abruptly grow into huge, slimy creatures with the capacity to launch slime as a weapon from their bodies. When a member states that there has been no trouble reported, the Commander addressing the members states that communications with Bazoik have been interrupted, and the Federation cannot contact anyone.

Luckily, the scientists from the Federation have found a way to counter the threat. Although conventional weapons do not affect the slimy invaders, the scientists have modified the "zorchers", the main weapon of the Federation, to effect a transportation of any object into another dimension, and this is demonstrated to those present.

With this new weapon the Federation believes that it can subdue the threat by sending a lone volunteer to the surface of Bazoik. The crowd discusses this for a moment, and a warrior from Chex Squadron declares he is willing to take the rescue mission. Taking his ship, he flies to the planet and begins his quest.

Levels

 * E1M1: Landing Zone
 * E1M2: Storage Facility
 * E1M3: Laboratory
 * E1M4: Arboretum
 * E1M5: Caverns of Bazoik

Chex Quest 2
Chex Quest 2: Flemoids Take Chextropolis is the second installment in the Chex Quest series, released in. It is an add-on to the original, as the first Chex Quest is required to play it. In this sequel's plot, the Chex Warrior returns to his home planet and lands in Chex City only to discover that the Flemoid threat has reached his homeworld. There, the player battles through a terrestrial spaceport, a cinema (showing three videos each endlessly looping), a museum, and the eponymous city, Chextropolis, until reaching the sewers to confront an end boss named "The Maximus".

Chex Quest 2 was available only from the games' official website, and only for a limited time. The basic gameplay is the same as in the first Chex Quest game, though some enemies have been changed cosmetically. Game development on the sequel was rushed to completion, with a lot of graphics being reused from the first game and the levels lacking in detail and quality.

Levels

 * E1M1: Spaceport
 * E1M2: Cinema
 * E1M3: Chex Museum
 * E1M4: City Streets
 * E1M5: Sewer System

Engine
Chex Quest comes with an executable called. This is a modified version of the Final Doom engine code that changes the engine in subtle ways that are hardcoded into the executable. Among these are new behaviors for the level warp cheat, longer text strings, and changes in weapon and enemy behavior. Despite its differences being subtle, they are significant enough that Chex Quest as such cannot run in Vanilla Doom and thus has to rely on its modified executable in order to function properly.

DeHackEd patches
Two DeHackEd patches exist that attempt to emulate the behavioral changes seen in :
 * The author of NxDoom, BlackAura, created a patch called on September 1, 2002. The patch was made to enable playing the game on a Sega Dreamcast.
 * Another, more extensive patch was made in 2008 by Fraggle. His patch was made from a comparison of  with Final Doom's version of.

Both patches do not emulate the executable fully, as the executable has to support longer text strings and cheat entries than DeHackEd can handle. Fraggle's version solves this by including a magic comments mode in Chocolate Doom, enabling long text strings and long cheat support and recommends running the patch either through Chocolate or through a source port that has extended DeHackEd support.

Projects based off Chex.exe
The Chex Quest community created several projects that require to function:
 * Nitro's Chex Quest (by Cory Scott (NiTROACTiVE) - A episode replacement for the original Chex Quest.
 * Nitro's Chex Quest 2 - Another episode replacement, this time for Chex Quest 2.
 * Chex Quest Advanced - A project to improve/remaster the original Chex Quest (And later on Chex Quest 2) whilst still operating within the limits of.
 * Chex Quest: Vanillavasion - A PWAD episode for Chex Quest Advanced, that can also run standalone with.

Chex Quest 3
The original Chex Quest 3 was made by fans of the series who were disappointed that the third had been canceled. But, rather than make entirely new levels and graphics, most of them were taken from other mods, including Hacx and STRAIN. This PWAD was noticeably more difficult. It was largely disregarded by the community when its unofficial status was confirmed. Team Eternity later started work on a different Chex Quest 3 project, but abandoned it.

Ten years later, Charles Jacobi, a former member of Digital Café, created and released his own Chex Quest 3, with cooperation from programmer Scott Holman and former Digital Café sound design leader, Andrew Benson. In addition to an all-new five map episode, the first two games were given a makeover and included as well.