A few quick thoughts - restart your pc. Any recent changes? New drivers, etc? Verify the game in impulse. Uninstall the game completely from impulse. Reinstall. Barring those options, you might want to send an email to support@stardock.com and see if they can provide assistance and send them your log files along with a link to this post. The logs can be found here:
C:\Users\USERNAME\Documents\My Games\Gas Powered Games\Demigod (update username)
useful files to send support: DemigodLog.txt, ImpulseReactor.txt, MiniDump.dmp.
Best of luck!