I started playing Knack last week, I played for a few hours and thought it was competent but nothing special. But since I stopped playing it last week I haven't had any desire to start it back up. Either the game missed the target it was aiming for, or it hit the target but the target was in the wrong place.
So I thought it was an action platformer, but it's really not a platformer at all. There's a fixed cam and no platforming challenge of any kind. So it's basically just an action game. The combat is not nearly deep enough to make it enjoyable, there is a dodge and a couple special moves and an attack button and that's pretty much it. Not nearly enough to make it a fun game.
But it's quite a bit more challenging than a Lego game. I can't imagine kids playing Knack the way they do Lego games, they would get too frustrated.
So Knack is basically an overly-tough Lego game with a terrible trophy list.
I never really read the reviews of the game, but I'm guessing they probably echo'd a lot of these sentiments. Maybe the game gets a little bit deeper further in the game, but I don't think I'm going to make it that far.