Right, I have managed to get this running without Admin on Galaxy and also in the usual way just clicking the shortcut on Windows 10 64 Bit.
I was getting random lock ups during the opening cionematics and various bugs and glitching in the game itself, missing the pic top left, no text onscreen at opening, missing mouse pointer and so on.
I tried messing with Glide (NGlide & another wrapper) and forcing 3DFX etc in the ini file and no go.
I then updated to latest NVidia drivers as there was a new one a few days ago I didn't know about.
So first up just download and install in the usual way through Galaxy.
Follow what Cyboff above has said about Directplay (mine auto started and installed this step)
Next up head here and run the installation : http://www.microsoft.com/en-us/download/details.aspx?id=8109
Now go into your Revenant installed directory and the shortcut (not the Revenant.exe) the one called Launch Revenant right click and select properties.
Under compatability tick Run this program as Administrator and then Apply
Now right click revenant.ini
I changed a few options, main thing is that you need to leave it running as Software3D, if you force no here the game will be missing the mouse pointer, character on right side inventory, text ingame and the avatar top left side of the screen.
My revenant.ini now (only made changes in Lighting and Options headers) :
Now run the game in the normal way through Galaxy and you should have no more crashes and be able to play it just fine.
I am going to keep tinkering to see if I can get some form of 3D Acceleration going, maybe trying out borderless window mode, if I suceed will post up, this should get you going for now though.