Are you wanting to add control objects (like scores, healthbars, level numbers, etc) into a scrolling world? Most scrolling classes have two ways to add objects into the world (or two super actor classes). One is for the scrolling objects and the other is for the non-scrolling objects. Refer to the documentation of your scrolling engine.

No, it's basically for a game in which you place pools of poison. the world is stationary. The DoctorProfessor is out!