I haven't read the post (but the_clown's - thanks for that )
However: On Topic: In the AU Recources you can find a 2D Sidescroller Super Mario "clon" by me (below "Demos") It is old and unclean but it could give you a start. Second: there is an aum about the 2D scrolling - AUM 85 Also: The aum from 81 to 85 are all about 2D games