I never noticed this before, but now I know, there is a HUGE difference. On the SNES version, its like there is a lot more room for Mario to move around in as well, and that's not just because of the image size. There's a much larger gap between the wall and the Chargin' Chuck. If Mario where to land between these, Mario would have lots of room to move around in the SNES version, but little in the GBA version.