This still uses the old SubOffscreenA routine, which was a thing in the first version of GIEPY. If you plan to use it with C3 version of GIEPY, you should rename all instances of SuboffscreenA to Suboffscreen in the asm file.
This is a rather simple platform but it could be quite useful. The sprite itself works just fine, but you can really improve the graphics routine - it's a bit of a mess right now. During the moderation, I added the sa-1 tag because the sprite works just fine with SA-1.