While some of the footstep sounds are OK, many of them sound like someone whacking the ground with a stick. There is also no variation in the step sounds, so they are all "clunk, clunk, clunk, clunk". It would also be nice if the sounds could be standardized a bit more in terms of length and the general footfall sound so they blend together better. I have been looking at the terrain.ufo file, as well as the team_*.ufos. The team ufos have lists of sound files for wounding and dying sounds for the various units. I think the same thing could be done to the terrain.ufo, allowing each terrain to have multiple footstep sounds, perhaps with alternate sounds for crouched walking, heavy steps (like Ortnoks, Power Armor), spiders, tracked, wheeled (UGVs) etc. as needed as well as grenade bounce sounds. The code should be very similar to how the team defs are parsed and used. Terrain.ufo also needs new entries for the added textures, as well as bouncefractions set in each.
I don't know that much C++, but I think I may be able to figure out well enough how to reuse the existing code to create the new structure. It will still be a lot of work though. Is anyone else working on something like this?