I don't know why you're getting downvoted for this; ANH gets resubmitted every time they do a new edit of it, and gets the same PG every time, but they've had to trim the movie down to keep that PG.

We still don't know why exactly Greedo shoots first in the cantina in the newer edits, but one of the more smell-test-passing theories is that the MPAA griped about Han, a heroic character, gunning Greedo down in cold blood and threatened the movie with a PG-13 unless they changed it (and Lucas' apparent displeasure with having to make the change, with him going around wearing Han Shot First shirts in public, seems to indicate it wasn't his idea even if this isn't the case).

On top of that, while it's way, way more subtle, in the shot where Obi-Wan cuts that one alien's arm off, the current edits have the shot last for a much shorter amount of time (and, while I haven't actively checked against Harmy or 4K77, it seems to be a little zoomed in to hide the blood pool, with the blood being color-graded to be darker and more obviously alien). In the current edit, it's only on screen for about a second, whereas it's a pretty clear shot in every version up to at least 97 (the one I had on VHS as a kid).