I have a problem when retrieving data with the format set to json. The debug console says I have a syntax error which is located in the response from GiantBomb.
Looking at the other thread you created, it looks like you're trying to do an AJAX call, in which case you need to make sure you specify that you want a result in the JSONP format and that you specify a callback.
Here's an example I just threw together. Just plug in your API key and try it out in your console: https://gist.github.com/Chaser324/15546811139ed13956b0
Take note of the 'json_callback=callback' parameter which references the function 'callback' defined below.
@dynamic_cast: You're actually correct about that, and that's probably a better way approach it. I've corrected the gist to properly use the 'jsonp' and 'jsonpCallback' arguments of jQuery's ajax function (...my initial error was probably just due to lack of sleep).