Well I bought it and it seems you cannot really nicely set your resolution. At least in my case, independent on the res option I choose, the game sticks to a fairly low one (something like 640x480 or 800x600). Apart from that issue I cannot really tell yet since I hope for a patch before delving into it.
Does Red Fction 2 use nglide? If so, you might have to set your resolution via the nglide settings (using the configurator tool for the v1 versions and for versions prior to that it used an ini file).