The most evident flaw in both Dementium games was, by far, the barely cohesive narrative. That's not to say the plot was bad - really, I think "Dementium: The Ward" has one of the best stories in horror-gaming - but it's just so uneventful, and difficult to follow.
The driving question of both games isn't the source of the monsters, nor is it of who the Doctor is and what his ambitions are. It's did William kill his wife, and was it a result of his psychosis.
In D:TW, William is clearly tortured by the death of his wife, and he's confused as to whether he did it or not - which is all about psychosis, the main theme of the games. However, the game reduces the death of his wife to shock scenes, and treats his daughter like a series of gag scares. Ideally, the game should've given an answer in the form of an even more convoluted question, which I think they tried to do, but it completely failed. The twist at the end was BRILLIANT, but flawed by the fact that the narrative never delivered.
Dementium II was even worse. Only a quarter-stretch of the game was given to his wife (albeit, in which, William was forced to kill "her"), and his daughter was wittled down to a brief reference. What Dementium II did was focus on the Doctor and his ambitions...which is important, yes, but not as important as the question of his wife.
What happened to William's family explains why he was institutionalized (whether he actually murdered his wife in psychosis, or was innocent and admittedly wrongfully) to begin with. The more we learn about her murder, the more we learn about the actual events of the game - are the monsters a real, supernatural threat (as would be explained by him NOT murdering his wife), or are they the paranoid reflections of his tortured mind (as would be explained by him ACTUALLY murdering his wife)? This is how the writers SHOULD be progressing the narrative - but instead, they're trying to progress the narrative through William's conflict with the Doctor, which tells us nothing about how "real" the events of the game actually are - were the monsters in William's unconcious fantasy of D:TW actually, supernaturally real, or just figments of his imagination? Does he really enter a plane of supernatural evil and horror, or is the Plane of Anguish just another paranoid reflection of his psychotic mind? The answer to these questions is completely entwined with what really happened to his wife.