For those getting this error when trying to run the game from the loader:
action number 1
of Alarm Event for alarm 0
for object rungame: Cannot execute AlphaProject.exe
'C:\Program Files\Heretic Studios\Alpha Project - Demo'
And run the game by running 'AlphaProject.exe'. To avoid using the loader, you can always set a shortcut to the desktop from that exe.
Sorry for the trouble caused! I think it's a problem with the loader or the install directory. I'll look into it and see if I can fix it in another patch.