Doom v0.4

Doom 0.4 was an alpha version of Doom released to testers on April 2, 1993. At this point in development, a number of elements had already been completed, and it appears that the main features of the renderer were already in place.

Version 0.4 included the following features:


 * A spinning 3D title screen, which was removed before the release version of the game.
 * The engine could render areas with different floor and ceiling heights, textured walls and ceilings, and different light levels.
 * Prone feature (removed from final version)
 * Collision detection was performed against the walls. However, there was no collision detection with sprites (e.g. monsters).
 * Monsters appeared in some of the levels. Although they were animated, they did not move or react to the player or to other monsters. Early versions of the Lost Soul sprites were included in the WAD file, although they did not appear during play.
 * The player's weapon bobbed during movement and could be fired, although it had no effect on the environment or monster sprites.
 * The game included a basic, but non-functional, status bar.
 * Doors (but not any other moving sector types) work and can be opened with the alt key.

Levels
Version 0.4 included 13 levels, some of which evolved into levels used in Doom:


 * Level 1: E2M7. It has no Hell textures and is designed to be like "Hangar 2" in the Doom Bible. The Blue keycard room is a hangar with the number two near the center of the room and an electric track in the center of the room. The ground floor has large crate room with only three or so crates and an exit, corresponding with the Bible's description of the ground floor.
 * Level 2: E2M2. Again no Hell textures. It seems to be based off of Supply Depot 2 in the Doom Bible, as it has a crate maze on the ground floor, a maze on the second one and is the level after Hangar 2 (E1M1 in the alpha).
 * Level 3: E2M3
 * Level 4: E1M7
 * Level 5: E1M6
 * Level 6: Not used in the final game
 * Level 7: E1M4. Based off of Enlisted Quarters in the Doom Bible, as there are lockers and showers on the left and right entrances.
 * Level 8: E1M2
 * Level 9: E3M3. No Hell textures. Could be based on the Lab in the Doom Bible, as a sign on the left side says LAB, while the right side leads to a dilapidated area, which makes sense if it were the "old building" section of the Lab. The two holes in the wall on the left and right sides of the stairs appear to be guard posts, as they have large red hands under them.
 * Level 10: Possibly E2M4.
 * Level 11: Not used in the final game.
 * Level 12/13: Mentioned in the accompanying documentation, but were not actually included.