Well, I for one really liked the mechanical puzzles.
There's a certain charm to how they are built in the Syberia world
As for the characters - I never found them annoying. They fit the world they belong to.
The only thing I felt lacked a bit, was the ability to interact with
ALL the beautiful and interesting items etc. you encunter on your way.
The puzzles are - IMHO - quite logic and well integrated in the story.