Yep ditto. Only the last tutorial image showed; the others were black squares. Game seemed to do well otherwise!
(edit: also mousewheel rotation only works in one direction... not sure if that is intended)
One more thing that may need doing in that modification, if a monster death is required to trigger something to enable advancement. To be safe I should probably make sure that code like the last few lines of monster_death_use gets invoked for all the ghosts (and then maybe NOT do that part of monster_death_use when it actually dies). Will get back to poking around at that soon.
Edit: E4M7 is a nice test case (the vores at the end). Made a couple of changes so that that map is completable.
Edit 2: Checked that all maps are completable.
Having fun poking around with this! If you're interested in providing an option for visible (noninteractive) monsters BTW, I've been running this mod with a small change to make that choice available: https://github.com/neogeographica/quakec/compare/ghosts...ghosts_modified
(also a couple of bugfixes in there I think, to make sure that flying/swimming monsters spawn correctly when tourism is disabled)