-One of the main differences with this proto is that it runs fullscreen. This causes the framerate to suffer, however.

-It also has more detailed graphics, with textures that are closer to the PC version.

-Levels have yet to be simplified, and are instead the same as the PC version. For those who don't know, the console ports of Doom have more simplified levels than the PC version, and there are also less of them.

-There isn't any music (so it has better music than the final version) and there aren't any sound effects.

-Tapping mode and X turns God mode on. Mode and Y skips you to the next level (but will return you to level 1 if you try it on level 5) and mode and Z gives you all weapons, max ammo, 200% armor and all keys.

-Beating a level will almost immediately have you start on the next one, there is no stats screen.

-Nine levels are available, but due to an issue with the sixth one crashing, levels seven to nine cannot be played without resorting to hacking.

-There is no level select available at the start.

- Pressing start will bring up the main menu. The options menu only has options for music and sound effects to be on or off. New game lets you pick a difficulty, but the game won't start. The nightmare difficulty is also missing from this build.

-The HUD displays how much ammo you have for your guns.

-The screen flash that happens when you pick up certain items hasn't been implemented yet.

-There are some hex values on the screen at all times which track your movements, ammo, health and armor. The other one keeps increasing constantly.

-When the title screen appears, the screen is all white for about a second.

-A password option has been added to the main menu, but it doesn't work.

-A music track has been added, which plays throughout the proto -the track is called "At Doom's Gate". This rendition isn't very good, but it could be argued that it might still be better than what the final version got.

-The game no longer runs in fullscreen.

-The password option has been removed.

-The graphics have been changed, and are less detailed.

-The music track used in the previous proto no longer plays.

-The hex values have been moved to the bottom right of the game window. The value that kept increasing in previous protos no longer does so.

-Press mode and X together will send you to the next level. The other cheats featured in previous builds no longer work.

-Using the level skip on level five will cause the game to crash.

-Levels have started to be simplified, meaning less areas, but some are still larger than the final version at this point.

-Trying to use the secret exit in the third level will result in a crash.

-The main menu now has an option for "level", but like everything in this menu, it doesn't work.

-The options menu also has a control settings option in it, but it doesn't work yet.

-"At Doom's Gate", which was last heard in the September 9th prototype, returns in this one.

-After the SEGA logo, a copyright screen briefly appears.

-The HUD has been updated and now lacks the ammo displays.

-The cheats from the first build now work again. The all weapons cheat now only gives you 500 of each ammo, like in the final version.

-You can now get into level six without the game crashing.

-Beating level eight will result in the game crashing, since this proto still only has eight levels in it.

-The red font has been changed, using a lighter shade of red.

-The main menu has been changed, featuring a wooden background.

-Many more levels are available.

-Options in the main menu now actually work, such as changing the controls or selecting a level.

-The level select option now works, but choosing levels 14 or 15 results in the game loading the first level. A few levels are still missing.

-The game seems to run faster in places -too fast.

-The border around the game window has been changed.

-The HUD is now fully functional.

-Beating the game results in another crash, as the game tries to load another level.

-The copyright screen has been changed.

-A title screen has been added, featuring the Doomguy.

-The music has now been added, and "At Doom's Gate" has been changed to what the final version has.

-Levels missing from the previous proto have been added to this one, bringing it in line with the final version.

-A sound effect is played when cycling through menu choices.

-The levels have have their edits made to simplify them, and the graphics are now fully downgraded to what the final version has.

-The main menu now has a demo game playing in the background, but it doesn't work -the player will spin around in circles and then stop moving.

-Some additional hex values appear above the HUD.

-Sound effects have been added, such as noises for when guns are fired, monster screams etc. However they seem buggy, as sound effects can cancel each other out, or not play at all.

-The cheats from the previous prototypes no longer work.

-The title screen's copyright date has been changed to 1994.

-There is a random red pixel at the bottom left of the title screen.

-The main menu demo now works.

-The nightmare difficulty setting has been added.

-The prototype for September 25th has another hex value on the game window's top right corner, but other than this it seems to be the same as the previous proto.

-There is a proto for September 28th, but there doesn't seem to be anything interesting about it.

-The October 8th proto gets rid of that random red pixel on the title screen.

-There is also a proto for the 1st of December, it doesn't seem to have much of note.

-There are also prototypes available for February 15th and 21st, along with one for March 7th -1995! These builds came after the final version was released, nobody seems to know what they are, and if they have any differences to the final version in any way. The fact that the game was still being worked on after it was released has led to the theory that SEGA might have planned a new edition of the game, but this never happened.