Prefix: I have not purchased the game yet, but I have played out the trial a bit. This is just my reaction to the plot so far.
First off, the graphics are definitely beautiful. Even better than the Blackwell games, if I might be so bold. Definitely quality work, and I'll enjoy exploring it further later.
Second, I like the medal system. It's pretty innovative in a way. And it's an easy way to tell your progress in the game. I knew as soon as the medal-colour changed, that I was in a new chapter. I also noticed the tab at the beginning allowing the medals to be reviewed. I don't know what that can do, but it can be a sort of bookmark for how far in you can get.
Third, the buttons. I think that's an interesting way to have collections out there that are completely optional. I'm half-way surprised it didn't have your standard commentary running through it, but I suppose the sketches add that personal touch.
Speaking of the commentary, I will make my one discussion of plot points here. Those who wish to avoid spoilers, look away now.
Still reading? You've been warned.
The bottle of Green Liquid. It reminded me of something you said in the Blackwell Legacy commentary. Couldn't think of another way to make certain Petra had it going into the dungeon?
Otherwise, bang up job so far. The puzzles haven't been bang-your-head-against-the-wall tough, but offer a nice challenge and a decent chunk of Ozian lore. I actually read the first Oz book after learning that Emerald City Confidential was being released, just to see how it varied from the movie. I'm having fun checking out all the colours, including the Scarecrow and Ozma in white dresses...