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.
Is that all the code? You also need an update function (besides create()), otherwise the program just ends. You will also need to add the circle to the state. Using your example:
class PlayState extends FlxState
override public function create():Void
circle=new FlxShapeCircle(100,100, 100, null,0xFF8899);
add(circle); // add circle to the state so it's displayed
override public function update(elapsed:Float):Void
@dean That fixed it! Downgrading to 4.0.8 just gave me linker errors, but installing rc3 worked. Thanks for the link too, it's good to see it's being worked on, especially since haxe 3.4.7 and hxcpp 4.0.19 are currently what you get from a clean install by default. Hopefully we get a full 4.0 release soon :)