Jack Black was funny once, at the beginning of his career when he presented something new and interesting, let's say refreshing...for a while. A very short while, turns out. If you look at his portfolio of movies, his roles are always the same. His voice, his gestures, his mimmick, his tone. The guy doesn't change anything, his acting limit is pretty much on repeat all the time. Also, his singing abilities are seriously irritating - especially in Gulliver where there is no fucking reason for it yet...there it is.
Amanda Peet didn't need this role, nor did Emily Blunt. Also, I can't explain what's Billy Connolly doing here and could only state that, if contrasted with Jack Black, the only other actor who sucks so much in this version of the book is Jason Segel (the guy just can't pull off the British accent, it's excruciatingly painful to listen to him).
You all know the story and how it ends. Jonathan Swift is not only feeling restless in his grave but probably spilling gas all over himself, lighting his bones on fire and stuffing Jack Black's ass with his ashes. Hope it hurts.
2 out of 10.