In the video game industry, third party licensed games are often the result of pitch demos. A developer will approach a publisher with a demo for a game, using characters they may not personally own the rights to, with the intention of being allowed to work with the publisher and its brands. Sometimes this leads to publishing deals and released games – but sometimes the projects do not get picked up, and those games quietly vanish.
This situation is what leads us to today, seeing footage and a playable build appear online for a Darkwing Duck game that Sonic Mania developer Headcannon pitched to Capcom. Capcom is the current rights holders for the NES Darkwing Duck game, and Headcannon's pitch was for a direct sequel, developed in the style of a SNES or GBA game. You can see video of the pitch demo above.
Each character would be pixelated from James’ art, and each level would be bridged by a chapter break, presented in motion comic form, with full voiceover and sound effects. And yes, you’d have gotten to fight Wolfduck. ?
— Aaron Sparrow (@Aaron_Sparrow) January 7, 2019
While Capcom didn't accept the pitch, you can play the unfinished game on PC here. If you want to play it, you might want to grab it quick, as publishers often take moves to get unofficial fan game content removed from the internet, particularly once a project gains attention.
While seeing pitch demos online isn't a common situation, it's a fascinating glimpse behind the curtain of how some games start out.