I suppose that this is partly because a) this is an adventure game marketed to a casual game audience, so difficulty expectations are lower b) this is an unusually narrative adventure game in which getting stuck for a long time would be a disruption of the intended pacing.
The puzzles are fairer than graphical adventure puzzles of the past, but many of them are so blatantly hinted that the player is deprived of the pleasure of really solving them. In other respects, the gameplay is fun but sometimes too directed. Moreover, when it wants to represent characters who are "busy", it will sometimes put them into a loop of repeating dialogue while the player solves some puzzle.
The game unabashedly repeats character dialogue verbatim if the player needs to hear some hint over again. There are many fetch-quests, and the occasional lock-and-key or get-x-use-x puzzle. The magic system's Enchanter-esque spells are strangely specific in their effects and conveniently work only when the designer wills that they should. It is a very linear game with carefully directed gameplay. Structurally, ECC is not doing anything especially new. The protagonist, Petra, is a film-noir-esque detective led to explore deeper and deeper into the web of lies at work in the Emerald City of Oz, which is not really at all the way you may remember it from the books she spends most of her time questioning people and solving some not-too-difficult puzzles. Emerald City Confidential is a graphical adventure by Wadjet Eye Games, under the creative direction of Dave Gilbert.