Chex Quest, made by Digital Café, is a total conversion of The Ultimate DooM. It was released in boxes of Chex Cereal in 1996, becoming the first game to be included in a cereal box. When it was released, it increased sales by over 200%. It then went on to win both the Golden Reggie Award for Promotional Achievement, and the Silver EFFIE Award for Advertising Effectiveness.
With GZDoom backporting video playback from Raze, I was able to get the intro and ending cutscenes for Chex Quest 1 working for episode 1 of Chex Quest 3. Enjoy!
I'm impressed! I wonder how SMK can be made or converted. Like say you take an existing video and make it into SMK. If that's even possible. If so, this could be awesome to use for future mods some day.