I had an idea while at the toilette, a classic! Just a guess: do I have to use an additional camera to trim a rectangle on the current rotating camera (that I will set as a bigger square)? I think it could be the correct way to make a topdown game with a rotating camera/level, unless Flixel already embeds a method to do it.
Because it would be the slowest part of rendering. My example may not be the best, because copyPixels in new versions of OpenFL is really slow anyway, so you don't want to use it unless you are ready to do some optimization work on it
Note that I'm talking about native targets, flash target is mostly unchanged AFAIK