The YouTuber in question goes by the name stacksmashing and as you’ve undoubtedly surmised, this is clearly not the man’s first time in making games run on consoles that clearly weren’t designed to support them. To be fair, stacksmashing did rope in the aid of another enthusiast by the name of Konrad Beckmann to help him out with the project. If it wasn’t made clear at the start, getting Doom to run on the Game and Watch clearly isn’t official and a fair amount of tinkering had to be done before stacksmashing was able to run the game on it. stacksmashing eventually managed to load Doom on the Game and Watch, but not without setbacks. While it did run, its overall performance was, in a word, horrible, and this is after he removed the in-game textures. Further, loading took the handheld console several minutes, while rendering a single frame would take several seconds. The good news is that Beckmann eventually figured out how to increase the CPU and flash performance of the Game and Watch dramatically, making Doom more playable on the Game and Watch. Mind you, textures were still virtually non-existent, but at the very least, stacksmashing was able to get it running at acceptable framerates. (Source: stacksmashing via YouTube, Hot Hardware)
