The man behind hit cinematic games Indigo Prophecy (Fahrenheit) and Heavy Rain has stated in a video interview that he doesn't mind making sequels. Skip to 5:13 below.
"Why not? It's not like it's a rule. when you spend so much time working on something and put, pretty much your soul into what your doing, once your done with it you need to move to the next thing...I don't like so much to go back and revisit what I've done. I like to move forward and try something else. But it doesn't mean we will never make a sequel because maybe we will find a story in which we will have something else to say, maybe it's going to be Beyond."