I picked up Dark Void last weekend, when it was on special from Games for Windows - LIVE.  I haven't bought everything they've had on special, but I've gotten a few things from them before (Arkham Asylum, Viva Pinata) and been satisfied.   The GFW-Live client itself... that's another story. 
 
In Dark Void, I've played up to the point in the second level/chapter when you (SPOILER ALERT) pick up your first gun.  Right after the short in-game cutscene, the game crashes to the desktop, every time, without fail.  I've turned down the detail, turned off Vsync, turned on Vsync, reinstalled the game, installed the latest graphics drivers...  I have never been so stymied by a game due to technical issues.   I've found very little with Google searches - probably due to the low number of people buying & playing this game.  If anybody has any other suggestions, I'm all ears. 
 
Not sure if this is a GFW-Live issue, a developer issue, or just my PC - although I have run games that are much more demanding.  From what I've read at other places online, this game has numerous bugs that need to be fixed, but I doubt Capcom or Airtight will fix them at this point.