It certainly has been reviewed a bit extreme from what I heard. Critics were crazy harsh about it, but normal people who went and saw it (regular movie goers, not just WoW fans) gave it tons of praise.
From my critic side I can definitely see some flaws. Comparing it directly to lord of the rings, or even the Hobbit as a better example, the dialouge could've been much much better. There were times when two people were supposedly completely surrounded by the enemy, orcs at that, yelling and sword fighting but yet these two people were having a completely calm conversation using their inside voices. There was also inconsistencies regarding an orc lady. At times she would speak in broken English, having only just learned the language, the immediately in the next scene she was speaking with perfect mannerisms and formalities and then a scene later back to using basic words. If she had gradually gotten better as the movie went on that would have been a beautiful touch.
With that being said, the CGI was AMAZING. The world felt incredibly rich and all the details on everyone was extremely well done. The amount of little touches and nods they had to the Warcraft universe really shown through in the first half and the fighting felt very impactful. They paid extremely close attention to the lore and there was only one part that really didn't make any sense since they switched one of the character's genders from being a dude to a chick... but otherwise everything was on point.