I found myself preoccupied with the main conceit of this film..that is, the overt "Film Noir"/ Chandleresque(some say Hammet) dialogue,wherein , the main/sympathetic characters speak in a poetic, elliptical , knowing and wise-cracking style..
Go with it ,and it is a familiar and enjoyable ride, with recognisable stock "noir" characters..the "femme fatale" , the geeky "expert" friend,and of course, the main character , the maverick "lone sleuth "/ "gumshoe", taking the law into his own hands, and getting beaten up a hell of alot,in the process....Joseph Gordon-Levitt is great,and this is enjoyable ,but nowhere near as good as it thinks it is...