I'm kinda new to this whole thing so bear with me if I make (a large number of) mistakes. :P

In the original game, tiles were either completely solid or not at all (in front or back of the main character) or as part of the parallax background, not sure how to go about remasking.

As for the compatibility, I didn't even realize there was a problem to begin with :P, a little more insight would be appreciated

Edit: Original game screenshots