Tip: Take advantage of easy to install Patches in your hack. The No More Sprite Tile Limits or SA-1 patches should be considered if you're encountering glitches where Mario and/or sprites are turning invisible.
This can be handy for puzzles, especially with the new mode for killing all sprites on a close Y position.
During moderation, I removed a single BRA on line 117. This fixes an incredibly obscure bug (I didn't manage to reproduce it in practice, which is why I didn't count it as a rejection reason) which theoretically allowed the sprite to kill a sprite it's not supposed to (the kill routine clobbers $00 and $01, then branched to the proximity routine without recalculating them). The only change in functionality is that now only one sprite can be killed per frame, which is not noticeable because the bug practically prevented more than one from being killed, anyway.