Pretty easily in point of fact: "I think it's good," or "I think it's bad" would work and can't really be gainsaid. You could also even claim "a majority think it's good/bad," and that is at least somewhat provable via a poll or ranking website. The point is that art is not objective, and as art, neither are video games. Someone else is always allowed to disagree, and that's there own subjective opinion on the matter, which doesn't invalidate yours if they disagree.