I had two runs on this game.
The first time I got very annoyed, because I had the feeling I've missed two puzzles in a row, so I stopped playing.
I'm a fan of Lucas Arts adventure games and I really hate games having dead ends. So I searched on internet, but I found the game doesn't actually have dead ends: missing a puzzle only leads to one of several possible endings.
I gave it a second try, this time with the proper mindset, and I found myself playing until 5:40 a.m!
The story is on the same verve of Beneath the Steel Sky: the dilemma between man and machine; allthough I've found it more engaging, with more relatable characters.
The puzzles are mostly fair, although a couple of them are quite far fetched, but you can always ask crispin for hints so you won't get stuck.
Towards the end, I wished the game were a bit longer, since there are many locations that are only named but you could never visit.
Another slightly annoying thing is that an event sometimes will make some object available in a place you've already searched. Fortunately, if you ask Crispin he will always direct you toward the correct path.
Overall, a great adventure that you're going to play several times, in order to see the different endings.
Highly recommended.