I downloaded DemiGod yesterday.  

Failure in that  it wouldn't start from Impulse -- though Impulse increments the Play Count.

Tried to start DemiGod.exe from Windoes File Explorer, that didn't work  (Aside:   I don't have a webcam.  I don't run COMODO firewall.  )

Success   What did work.  I opened a DOS command prompt, changed the director to the Demigod\bin directory, and entered Demigod.exe

There is an anomaly in that the I where I had told Impulse via Preferences, after it ran out of space in the download (apparently it is unable to check for disk space), is not where the game actually was installed.   Impulse does know where it is -- asking Impulse to open of the application folder shows where it really is.

@hstuck

Try creating a shortcut to demigod.exe and in the properties for it (right click and select properties) add the following to the end of the Target field:

/purgecache

make sure to include a space between it and the existing text in the field.  Once you do this, load Demigod again.  After you close the program, remember to remove the /purgecache tag as you really don't want to load with it everytime because it will add to loading times.