@function404: Hey there! I'm very sorry to hear you're running into trouble. Although the app isn't really supported any more at this point, if you're not able to get things working in a browser either it sounds like it may be a bigger issue with iOS 9 and not just the app itself.
The first thing that came to mind was that it's possible that the Giant Bomb website and/or video server is requiring newer encryption than iOS 9 supports, in which case the two wouldn't be able to talk to one another. I did a little poking around though and, as best I can tell, that doesn't appear to be the case. I'm afraid I'm at a bit of dead end but hopefully Giant Bomb's Top Men can offer some additional insight.
Sorry I can't be of more help, but thank you for keeping the GBVB torch alive all this time!