windows7 firewall you need to allow traffic manually. It will ask for you to allow on run but that's only one way allowance, you would need to allow in and outgoing for demigod in your firewall exceptions.
Also ports to forward are 6100 to 6200 traffic type all. Also for multiple/lan you need to specify the nat range. Run Impulsereactoroptions file in the c:\stardock games\demigod\bin folder. set a range of 20 different on each pc (run this file on each pc) in the network: for example pc1: 6112-6132 , pc2: 6142-6162. Then in your router forward this same range for each pc's IP.
Any more than 2 pc's on the network don't bother trying...and only try more than 1 on cable or very fast UPLOAD speed adsl.
For security turn off port forward after play and have a good time!