Jamie Bell's in it? Sigh... Oh well. He's really not the picture of confidence in any of his movies, just a nervous little fellow. Tintin's always been more sure of himself than any character I've ever seen Bell play.
As for the game, it can almost really only be an adventure game, with puzzles and the like. But I'll bet they go 3rd-person shooter. Well, at least we know they were given two years to work on it.