@lac: I've just got an idea how to solve your problem. It requires an enormous amount of work, and it's very boring, and not so straightforward either, so I don't know if it's worth the effort. But, it's a solution. Here's what to do:
1. Download a DAT extractor (there's a list
here) and unpack critter.dat.
2. Backup the folder data/art/critters.
3. Enter data/art/critters (not the backup - the original one). There should be a loooong list of files called HANPWRAA, HANPWRAB, etc.
4. For each type of critter (so HANPWR, HAPOWR, etc.) you need to take the frm file (animation) with the ending of BA, or BB (depending on whether you want your critters to die when falling front, or back), copy it several times and rename (the copies, not the original files!) them as follows:
BD - HOLE_IN_BODY
BE - FALLING_BACK_BURNED
BF - RIPPING_APART
BG - PERFORATED_DEATH
BH - FALLING_BACK_ELECTRIC_BURNED
BI - SLICE_IN_TWO
BJ - FALLING_FRONT_FIRE_BURNED
BK - ELECTRIC_BURNED_TO_ASHES
BL - BLOW_EXPLOSION
BM - MELTDOWN
BN - BURNING_DANCE
BO - BLEEDING_BACK -> this should be made out of BA animation.
BP - BLEEDING_FRONT -> this one from BB.
5. If you have the file patch000.dat (in the main F2 folder), rename it or remove it.
As you can see, it's hell of a lot of work to do, but it will ultimately remove the gory death animations and replace them with the standard fall back/fall front animation, without even the on-death blood.
So if you're really desperate about removing blood and gore, this is one sure method that I can think of.