We also set some rules for our project. The chocolate-doom source code is available, however, we did not want to reference it at all. Once extracted, chocolate-doom.exe was a stripped PE32 executable. This meant that reverse engineering efforts would be a little harder, but that was part of the challenge and learnings we wanted. Using tools such as IDA Freeware, CheatEngine and WindDBG was considered fair game though. However, any patches or binary modifications had to be implemented using Frida, and not by manually patching chocolate-doom.exe.
The game is the first to be developed with the id Tech 7 engine. According to Stratton, the team aimed at making a "Doom universe", featuring larger and more varied locales, including "Hell on Earth", for players to explore. Unlike its predecessor, id Software developed the game's multiplayer component in-house, as opposed to being outsourced to the previous game's multiplayer developer Certain Affinity, with the goal of making the experience more "social" and "connected" with the single-player campaign. The team decided to remove the SnapMap mode and reassign its resource to develop post-launch campaign downloadable content. While originally scheduled for a release on November 22, 2019, Doom Eternal's release was later pushed back to March 20, 2020, with a Nintendo Switch port coming at a later date, which on November 30 was revealed to be December 8, 2020.
The Doom Classic Unity port is a series of official ports of Doom and Doom II initially developed by Nerve Software in cooperation with id Software and first published by Bethesda on July 26, 2019 as part of the "Year of Doom" promotional campaign. It was initially announced on stage during the QuakeCon 2019 (DoomCon) keynote presentation. The port is based on the Doom Classic codebase, but replaces the id Tech 4 shell with one based on the Unity game engine. This offers immediate portability to a wide array of targets - the Doom and Doom II ports were available at initial launch for the Sony PlayStation 4, Nintendo Switch, Microsoft Xbox One, the Google Play app store for Android, and Apple's iOS app store. The January 9, 2020 patch added a PC version via the Bethesda.net distribution platform. This was also extended to the Steam distribution platform by the September 3, 2020 update. As of August 17, 2022, it is now included with the GOG versions of Doom and Doom II, and as of August 18, it has also been released on the Epic Games Store.
The arsenal made available to players in DOOM Eternal is extensive and overall familiar for veterans of the series, with the notable exception of the missing pistol typically used at the start of most other games. As it turns out, the development of the game did include the classic starter weapon but it may not have fit the flow of combat wanted by the designers, so it was removed from the main game but is accessible with the use of the cheat engine table. 2b1af7f3a8