I just went on to the NZ psn and saw Knack 2 "free" downloading it now and says it's the full game. Even came with a soundtrack. Might be a glitch.
Edit: I'm playing it now, the funny thing is i just bought this today but its on the way in the post.
Edit 2: now some other website is also reporting it: http://www.3mglive.com/knack-2-available-download-new-zealand-psn-store-free-heres/