I spent the last few weeks learning NES ASM, so I can make this game engine as similar as possible to the original.
The first step was to know the control points that the programmers had used for the main character. It took me a lot of time until I finally found the routines for this... And there were two sets of control points: the normal one, and one that is only used when Kid Dracula is walking on the ceiling.
I also added a function to load map files that I'm creating with an external tool, so I can make better looking levels very easily:
Yay.