Doom 2D

Doom 2D is a fan-made DOS-based freeware side-scrolling video game based upon Doom, similar to Doom 2D - Knee deep in the dead. Doom 2D is essentially the original Doom translated into a two-dimensional arcade or console-like shooter, comparable to the original Duke Nukem. The player resumes their role as Doomguy, who must do battle with various hell-spawn.

Originally appearing entirely in Russian, eventually a partially-translated English version appeared and both are still available for free on the Internet.

Story
The story of Doom 2D is presumably the same as that of the original Doom, which contained very few story details in-game. Doom 2D has even less in-game plot developments than this, simplifying the already simple objectives found in Doom games.

Gameplay
Gameplay utilizes a simple and customizable set of keys to navigate a 2D environment and defeat and pass monsters. The game also offers splitscreen mode for two-player cooperative-play or deathmatch options, which can be played using different keys on a single keyboard.

Visual styles and creatures
Two new monsters added along with original Doom ones (exception is spectres), as Doom 2D utilizes the monster sprites (and others, such as object sprites) ripped from the original game. The creatures are seen from the side (as opposed to the front, as it is in Doom) due to the different perspective. All monsters are completely deaf (even the players' shootings never wake up the monsters as long as the shots do not hit them). The game features foreground and background pictures both taken from original doom and new ones (though many of them are unused). The sound effects in the game are also taken from the original doom but are played in poor quality.

Maps
The game features 19 maps without secret levels, though they can be still used in custom levels. Authors claimed that they tired of making these maps, therefore so few maps are made. The map size is always of 100x100 dimensions.