Playing the Original 'Doom' Inside 'Ultrakill': A Modder's Ingenious Creation

Relive the Classic: Doom's Unexpected Comeback within Ultrakill

The Ubiquitous Reach of Doom: A Gaming Phenomenon

Doom, the iconic 1993 creation from id Software, continues to demonstrate its remarkable versatility, running on an astonishing array of devices. It seems far simpler to list the platforms incapable of supporting this masterpiece than those that can. Yet, a truly special kind of satisfaction arises when a game is successfully embedded within another. This unique pleasure has been perfectly captured by Squaresweets on GitHub, who has engineered a fully playable version of 'The Ultimate Doom' directly within New Blood's high-octane FPS, Ultrakill.

Ultrakill's Seamless Integration: A Shop Terminal Transformed

In Ultrakill, every new level commences with a cleverly designed in-game shop terminal. These terminals, reminiscent of those found in games like Prey or the more recent Deus Ex titles, allow players to fluidly interact with the interface using their mouse to select loadouts without any disruptive pauses, movement restrictions, or intrusive UI overlays. This seamless, diegetic interaction is a detail many players appreciate, and now, the robotic protagonist V1 can utilize this very terminal to indulge in some classic fragging before diving back into Ultrakill's intense combat.

The Technical Foundation: From Unity Inspector to In-Game Reality

Squaresweets' achievement is built upon the foundational work of other talented developers. Their project leveraged xabblll's 'DoomInUnityInspector' and sinshu's 'managed-doom' source port. Sinshu's port was crucial due to its implementation in C#, a language compatible with Unity. Xabblll then successfully adapted Doom to run within the Unity editor. Squaresweets subsequently finalized the project, enabling Doom to function flawlessly within an actual Unity game environment, making this in-game integration a reality for Ultrakill players.

Setting Up the Ultimate In-Game Experience: Installation Guide

To embark on this retro-futuristic gaming journey, players will require a .wad file from a version of Doom 1. This file provides the essential art and assets for Squaresweets' ultradoom.wad. It's important to note that, currently, Ultradoom does not support custom user-made projects like MyHouse.wad. The necessary DOOM.wad can be acquired from a legitimate retail copy of Doom, such as the Nightdive re-release, or through the freely available shareware version found on the DoomWorld forum. Additionally, the BepinEx Unity modding utility is required for installation. The straightforward setup process involves:

• Ensuring Ultrakill is purchased and installed.
• Downloading the appropriate BepinEx version (e.g., win_64 for Windows 11).
• Extracting BepinEx files into the Ultrakill installation directory and running Ultrakill once to finalize the BepinEx installation.
• Downloading UltraDoom, extracting 'ultradoom.dll' into the 'Ultrakill / BepinEx / plugins' folder.
• Creating a new 'doom' folder in the same location and placing 'ultradoom.wad' (from the mod) and your 'DOOM.wad' (from your Doom copy) inside.
• Finally, launching Doom within Ultrakill by clicking the smiley face on the in-game terminal's touchscreen.

A Nod to Gaming's Past: Retro Controls and Developer Acclaim

Once installed, players can enjoy Doom with its classic keyboard-only controls, utilizing WASD/arrows for movement and turning, and Ctrl for firing, just as the developers originally intended. Remarkably, the mouse continues to control V1 within Ultrakill, allowing players to disengage from Doom simply by looking away from the terminal screen—a thoughtful touch that enhances the immersion. This ingenious mod has even caught the attention of New Blood's esteemed leader, Dave Oshry, who publicly acknowledged and celebrated this impressive creation.

The Enduring Charm of Games Within Games: A Continuing Trend

The concept of a game embedded within another game consistently brings joy and a sense of wonder. Whether it's the Yakuza series offering high-quality emulation of classic Sega arcade titles, the appearance of a Johnny Silverhand-themed Wolfenstein 3-D in Cyberpunk 2077, or the surprisingly engaging ARPG playable within Night in the Woods, this meta-gaming trope always delights. As for Ultrakill itself, its development continues, with the next significant update for this influential and acrobatic shooter anticipated for release in the first half of 2026