Game of Thrones is an unattractive game. Granted, Westeros is an unattractive place, but the show doesn't portray the Seven Kingdoms as rife with blurry surfaces and empty towns. Characters often literally appear out of nowhere. Westeros is absolutely full of human misery, and the lack of NPCs in most towns (particularly King's Landing) is absolutely striking. Also worthy of note is the lack of gruesome violence. The most recent episode of Game of Thrones featured the image of a man getting his skull horizontally bisected. I'm a red-blooded American male, and my gaming philosophy isn't exactly "No blood, no boobs, no way." That being said, it's such an important part of this license that its absence is difficult to shrug off.
Sound design is hit and miss. The soundtrack doesn't reach the same heights as its television counterpart, but it fits the world perfectly. I especially like the deep, airy gloominess of the music played at Castle Black. Voice acting is extremely inconsistent, leaning mostly towards the bad side. Conleth Hill and James Cosmo reprise their roles as Varys and Lord Commander Jeor Mormont, and though their performances are identifiable, they aren't as vivacious and engaging as they are on the television screen. Leading characters Mors and Alester aren't much fun to listen to, though that's more a fault of the writing than the performance of the actors.