Running on Crossover Games 9.0 Mac version, on Snow Leopard, using Intel GMA950 onboard graphics, Emperor installs and runs flawlessly until it comes time to actually *play* a map. Once a game starts, the user is unable to see the map or the units; instead, there is just a black screen with the build overlay above it.
The issue appears to be whatever medieval texture compression Westwood was using in 2000. Fortunately, there is a quick solution. By running the game with the -c switch, texture compression is disabled and the game runs great.
To do so, simply navigate to Programs-->Run Command. Select your Emperor bottle, browse to the Westwood folder, and select "Emperor.exe." After that, all you need to do is add the -c switch to the end of the command line. The end result should look something like this:
"/Users/ME/Library/Application Support/CrossOver Games/Bottles/Emperor/drive_c/Westwood/Emperor/Emperor.exe -c"