First of all thanks for a great game - it has sucked up many hours of my spare time over the last few weeks!
I've been having startup issues. The same problems occur whether starting from within Steam or via the desktop shortcut.
(1) CTD when restarting a level from the main menu where the level had previously been commenced and then exited from (i.e. when prompted "do you want to resume or restart").
(2) CTD on a fresh start at the point where the main menu would normally show - i.e. immediately after "Defense Grid: The Awakening" title screen appears
(3) Getting stuck on "Defense Grid: The Awakening" title screen (does not freeze - animation continues, as does the theme music)
After (1) and (2) starts happening, the only way to fix it is to use the "verify game content" option in Steam, which would always redownload 1 file, after which DG would start up fine.
At the moment I am experiencing (3) and there doesn't seem to be anything I can do to fix it. The local game files verify OK and nothing has changed in my antivirus/firewall. All my other Steam games work fine.
I don't want to do a full uninstall/reinstall if I can help it. Any ideas?