But everybody knows about the problem. Many reviewers, outside the German market in case of bigger German games, only play the opening act.
So why not do what the big guys do: Polish the hell out of the first 5 hours, even on cost of the middle acts. This would lead to a higher score on average, simply because a number of reviewers wouldn't make it to the average stuff.
I'd prefer slightly more polish. I don't think it was an either/or proposition in this case (either have a good first 5 hours or a good rest of the game). Having a very weak opening is more than just a marketing and review problem; the first act of a game, play, movie etc. has importance beyond the superficial. It sets the tone of a piece and can enhance or detract from how voraciously and enthusiastically one delves into the rest of the content. While I would urge people to play through these opening segments and assure them that it does get better, I would prefer not to have to.
I do fault professional paid game reviewers who did not (if they did not) play past the weak opening. I would also fault them for allowing the weak start to color their analysis of the later game. I can not fault them for it detracting from their own ability to enjoy the later game though - only for the failure of some to recognize that many of these flaws were concentrated during the first act and that the effect they had on the enjoyment of the latter part were indirect. I can't let PB off the hook though for creating such a weak opening either.
So what does this mean? It means that for players with time and who can forgive a very weak opening (and the clunky combat and technical strangeness) that they will find many aspects of the later chapters very enjoyable and rewarding. In some ways, the middle-late parts of the game represent some of the best of what PB has done. That the introduction to this content is pretty bad is a shame and shows a great deal of uneveness in their focus and perhaps some failure to prioritize properly. If you enjoy PB games and can get past the beginning, you will probably enjoy this.
On the other-hand if you don't want to play through several hours of a "meh" game to get to the good parts then you probably don't want to play this game. If the combat in previous PB games annoyed you, this combat will probably annoy you more. So if you have not enjoyed previous PB games you will likely not enjoy this one either as the differences it has with their previous titles are not the kind likely to convert non-fans very easily (unless you have a pirate obsession maybe.)
On a 1-5 scale with 1 being awful, 2 being mostly bad with some redeaming qualities, 3 being definitely "good" but with serious flaws, 4 being excellent but with significant enough flaws to hold it back from true greatness, 5 being a great game and easily a future classic, and 6 being perfect and thus being a score not ever to be given…
I'd say it starts out at a 2.5, climbs to a 3 an hour or so in and by 20 hours in is somewhere between a 3 and a 3.5. On a 100 point IGN scale I think most of us might call this an 80-87 final score (since x/5 and x/100 scales don't really correlate very directly if you look at score averages for the same games.) For a PB fan it might even get as high as a 3.9/5 (roughly an 89-90 on the non-linear x/5 to x/100 conversion) but for someone who doesn't really like PB games you'll probably feel it never really even makes it to a 3.