Castle of Dr Malvado was originally one of the demo's that came with DIV. On the DIV disc were several games and a set of 6 smaller demo's to help you going with the easy concepts. Since they came with DIV they are copyrighted and not up for legal separate distribution, though those who want them can download the DIV demo version from div-arena here. They might not all compile directly, but the differences will be so minimal that they can still be of good help.
Nooooooooo, change it sooner! I want to try to make a completely walkable level (only had one screen yet, without scrolling) and want to use some of the code of this game!
But take your time,I just found some bugs to fix...