If you are talking about your MOD, the title screen just uses several small pictures pieced together. If you wanted to make a full background image, that would require more than basic modding.
I draw characters from video games and manga that I've read. I don't really have a favorite subject. I probably wouldn't actually use hand-drawn things for a game. I might start out with pencil drawings, but I'd go over it digitally.
The plan originally was to use it as the final boss theme, but since the creation of perfecta, that has been scrapped and so it basically would have gone unused.
Had to code in a bit after the part where the game draws the water (like in the core) a little part that would draw snow and other things if I choose to expand on it. But the "snow" itself knows where to draw itself through the Snow AI, an entity that's on the map that gives the snow code the drawing coordinates.
It isn't too hard if you know what you're doing, but it took me awhile to get to the point where I knew what I was doing with assembly and cave story :S
You want me to make a title screen for you? You mean for a MOD? I'm pretty sure that those are actually several pictures pieced together. I wouldn't mind doing something like that for you. What did you want?