@lewciooo1,
I don't really know the rule or the rationale, so I could well be wrong, but I think the following two sentences would be correct current useage:
1. Only
a few critics appreciated...
2.
Few critics appreciated.
I believe the difference arises because "few" can be used in either a (relatively) absolute sense or a relative sense.
By "absolute" sense, I mean that "a few" is often used to indicate a small number (at least three, but maybe four or five--its not always specific).
By relative sense I mean something like a small "percentage," say 10%. 10% is a small percentage, but, that said, 10% of 100,000 (potential critics) would still be 10,000 who "appreciated."
"a few" means 3 or 4 generally.
Few, without the "a," is used in a relative sense.
But, again, don't trust me if anything important is at stake. Otherwise, I think if you use it that way, it would be generally understood.