FlxSpriteGroup
- FlxSpriteGroup shouldn't exist, but Flixel's "easy to get into" mindset means it has to exist. So now, the class is halfway between AS3 (sprite grouping is the default) and Kha (sprite grouping is DIY)
- Issues: setting alpha to 0 is unrecoverable. MouseChildren handling subpar, especially compared to flash.display.Sprite#mouseChildren
- Potential solution: give FlxBasic/Object/Sprites a parent:FlxTypedGroup<> property and propagate that change throughout the lib
- Impact to lib: major
- Effort required: possibly a lot
- Breaking: mouseChildren behavior could be changed to match AS3's
Inheritance
- Flixel greatly relies on inheritance, which makes it difficult to use