I unzipped the files today and got the game running! It's only Aquatoids (they look the same), but a lot of other things are different. The game is apparently reusing UFO's geodata.dat file for the TFTD weapons so the aliens are ultra-vicious with 35 round mags for their sonic cannons. The standard aquanaut diving suit is yellow, but when killed, the corpse shows a blue suit. The aquanauts themselves stand with their legs far apart in an upside down V, which is really funny. All the weapons look mostly different. I was able to find the USO (looked similar to a Medium Scout in UFO, except a little smaller and with nothing inside) and kill the two Aquatoids. Just before I ended the mission I saw a muted-purple ball on the floor. One of my guys had enough TU to run over it and take a look - looked a little like Elerium did with roughly the same yellow crystals, but it had a band of red running through it. So my first impression is that this is GOLD!
Going to see if I can get it running under DosBox so that I can grab some screenshots for you guys to drool over.
Anyhow, I'll be adding more promotional item images starting tomorrow again, just wanted to give you all a heads-up on the test disks.