Megawad

Overview
A megawad is a fan-made PWAD that contains multiple levels, usually either an episode's worth of levels (approximately 8 or 9 levels) or a number of levels equivalent to an entire game (approximately 27, 30, or 32 levels). Megawads may be the effort of one person, such as Gwyn Williams's Vile Flesh megawad, or of many people, such as the Doomworld community megawad project Community Chest 2. Whether a solo or group effort, excellent megawads require a huge time investment and can require months or years to create. A megawad may well represent a Doom mapper's collective lifetime works, such as Jan Van der Veken's Classic Episode, which is mostly a collection of levels previously released as stand-alone wads.

Because a megawad is such a massive undertaking, quality megawads are few and far between. However, they are almost always the most anticipated PWAD releases, as well as the best remembered.

Full Game Replacement

 * 2002 A Doom Odyssey

Episode Replacement

 * Phobos: Anomaly Reborn

Full Game Replacement

 * Alien Vendetta
 * Hell Revealed

Episode Replacement

 * Dark 7
 * The Darkening Episode 2