Satoshi_Matrixcan that be fixed to make the game 'full screen'?
I know what you are referring to, I also hate that aspect of the game, but I do not know how to solve it, since it is not that the game draws any specific tiles there *, but everything that is under that line is eliminated, both the background and the objects

Despite this, by crashing the game it is possible to realize that originally the game if you draw the graphics in that sector. Another detail is that this line is not used in any of the transition screens between levels.
On the other hand I imagine that the function of this line is to hide the abrupt cut suffered by the waterfalls in Green Hill, since otherwise I can not make sense of it
SuperStarFox For the title screen I have two options: 1º One option is to see how to adapt my design back to the previously discovered limitations by creating a graphically lower version.
2º I can also choose to ask for help from someone technically better prepared to rewrite the operation of it in a way that best suits my design.
But as I said, I find myself working on other things at the moment, so I recommend waiting for him to publish some kind of update of the topic before asking another question about it.
About the rest of the project, I was not doing anything really transcendent: ● I was playing with some palettes configurations.
● I was solving some bugs in certain zones*.
● I'm trying some alternative graphics, for example:

On the other hand I discovered that in the game it is still possible to cross some walls under very specific circumstances, these bugs happen in the
"Green Hill" pipes, in the union of two different block types in
"Marble", and in the blocks of lions that touch the ground in
"Labyrinth", the latter are the only ones I already know how to fix.
Finally I would like to recommend the

gameplay that
SuperStarFox has made by trying an old version of this hack, in which you can see several interesting things that I have not commented on in my publications.