In this video, you can see an early alpha version of DOOM, a popular first-person shooter done by id Software in 1993.
Unlike the other prototypes, this one was not sent to testers, but to game developers of the time. It was shipped with several nearly identical stub maps with a single room, while the other levels are very early drafts of the final maps. The game engine in this version has been enhanced to render areas with different floor and ceiling heights, and different light levels. In the game, you can switch between the helmet HUD and a fullscreen HUD, that contains a small bar at the bottom. It is also notable that the helmet HUD has a working automap on the top right.
Read about the development history of DOOM: