Slightly different sprite clipping in Dday versus vanilla
This is a very small thing, but it is a difference versus Vanilla.
Here is a pwad made to test clipping of sprites partially under invisible floors; the 320x200 screenshot is from Vanilla Heretic, while the 1900x1080 screenshot is from Doomsday.
In Vanilla Heretic, all the key mobj's are visible above the invisible floors, but in Dday only half of them are.
The screen shots show two groups of six key's in invisible pits, one group with liquid flats and other without (the liquid flats weren't needed as key's are unaffected by the clipping).