The IBM PC came along in 1981 and it couldn't come anywhere near arcade perfect :). It took a lot of years before it got to that point. I wouldn't expect the Commodore 64 to be able to handle an arcade perfect port of Galaga but I think it could handle a good port. I'm certain you could get something with much better graphics than above. Regardless, I was just always surprised there wasn't an official one.

But that does seem to be the exact same game I played but with some color.

This looks like a pretty good clone but seems a bit fast