As I said in the other thread, I think it's very reasonable to believe that Knack is undertracked throughout EU. It is "Sonyland" after all.
Also have to laugh at people calling it mediocre or shitty, without even playing it, just because it's outselling SM3DW in the UK. I've actually played it, and it is definitely above mediocre. Kinda reminds me of a Crash game, simple, straightforward and fun. Only more emphasis on combat.