Reviewing a game is like taking a snapshot of someone at any given point in time. Comparing the picture of a 40 year old man to an older picture of himself taken 10 years earlier, there's a good chance that everyone could say that they were both of the same person without even knowing him. Yes, the hairdo and clothing might have changed, but that person's features would still be recognizable and pretty much the same as it was on the older picture. Single-player games are very much like that: they are released as mature, adult products that won't change very much anymore. A MMORPG would be more like taking the picture of a 6 months old child. Another picture taken even just a year later would show a huge transformation. Let ten years pass and there's a good chance that you wouldn't even know that the two pictures were of the same person.