Someone on the Steam forums posted this video on how to possibly avoid the crash with final parts from the last level, and I have used those methods on a clean Steam copy of the game with the last official patch and without cracks, however, instead of using Task Manager to force the game to use CPU 1, I forced CPU affinity to the executable with ImageCFG, that way I can just enjoy the game without having to reach over to my keyboard to force CPU affinity via Task Manager. From my experience, this not only let me see the scene where Dracula Duck fades away in its entirely without the game crashing, it seemed to fixed other issues of the final stage. I cannot guarantee this will work for everyone though as some other users who tired it and forcing the game to use only CPU 1 via Task Manager report it worked while others didn't.
I'm not sure if the game itself is also DRM-free since the copy I used seemed to have the original executable and related .dll files, but upon running the game it ran without prompting a Steam log-in.
Sources: youtube.com/watch?v=Ebf0fpfHNGI
https://steamcommunity.com/app/237630/discussions/0/864976115482880816/?ctp=17#c1642043267252258294