Ok, I'm having the exact same problem. After I installed Impulse then downloaded the beta, it would not run at all (exactly the same symptoms as others are describing: start Impulse, double-click Demigod and *nothing* happens - a second or two of the cursor switching to the hour glass then nothing).
I uninstalled the application and removed (deleted) Demigod, then re-downloaded and installed it again. Then it worked once or twice, and now it isn't working again.
This has happened over the course of the last week or so, and there have been *no* changes to my pc. I have also tried removing/disabling my antivirus application and it makes no difference whatsoever.
Please help!