Doom v0.2

Doom 0.2 was the earliest known alpha version of Doom released to testers outside id. It was released February 4, 1993, when only two months of work had been done on the game.

Features
The "technology preview" includes only one small level with no changes in elevation, no doors, and no items. Only three enemies are present—the imp, the demon, and the Baron of Hell—and their sprites and programming consist only of walking in place.

The only weapon, an early version of the shotgun, has no effect on the monsters. The texturing is scant, though a few textures and flats were modified and used in the final game. Floor, ceiling, and wall textures can be cycled individually by pressing the number keys 0-9. This may also change the ceiling height.

The heads-up display/status bar in this alpha is larger and more complex than those that followed. An automap, item list, and weapon stats are among the extra elements visible. However, at this point, all of the data shown on the HUD is purely decorative and does not change. There are two message areas. The left message area has text "Chen: Ooh, I found cool stuff" (possibly meant to be a communications/message window; "Chen" refers to Lorelei Chen, a character from the original design document), while the right has "Captain's hand, Sandwich, Heart of Lothar" (possibly meant to be an inventory window; again, the items are from the original design document). According to programmer John Romero the items were meant to function as different types of keys. The automap shown does not correspond to the actual level layout at all.

Texture cycling
Several of the keys on the keyboard allow various features of the engine to be controlled. One of these allows the textures on the floor, ceiling and walls to be changed. One selection for the floor and ceiling displays the words "TOM IS KING", while another selection displays "JULES SUCKS" on the walls. Jules, according to Doomworld's page of doom, refers to Adrian "Jules" Carmack. It is possible that "Tom" refers to Tom Hall.

Technical
The renderer and game engine of the 0.2 Alpha version was still in its' early stages. The engine did not make use of textures internally, but displayed the patches directly on the wall surfaces. Therefore the game WAD file does not contain TEXTURE lumps.

At this point the renderer made no use of the Z axis, so the engine was incapable of rendering levels with different floor heights.