I was getting a black screen when starting SPAZ. I threw this script into the SPAZ folder (the folder with SpazGame.exe) and ran it via the Programs -> Run Command… menu.
This does NOT solve the low framerate issues, just the black screen issue.
#!/bin/sh
sleep 3 && xgamma -gamma 1.0 &
/Applications/CrossOver\ Games.app/Contents/SharedSupport/CrossOverGames/bin/wine --bottle "Steam" --cx-app SpazGame.exe
sleep 1
xgamma -gamma 1.0
EDIT:
Note that you'll want to make this script a text file and will likely need to chmod 755 <name of file> to let it run.