I bought the game and i thought it would be a very long game(60h) but it wasn't.
The game isn't even the half of that.It's about 9/10 hours

GOG description:

"A gripping spy-themed storyline that will keep you entertained for over 60 hours"

why did the gog write something like this???
Is it an error?

Well, it wouldn't be the first time the publisher's description is used by GOG. :)

Awww man! That was why I just bought the game. Oh well. Its hard to get mad when it only cost me 2.39.