Jon of RealGamerNewz writes, "I have many positive things to say about Knack but at the heart of its core one thing must be respected. Knack is a pure 3D Platformer and defines the next-generation of its genre without the need for stealing elements from shooter or action games. Knack accomplishes a complete and fun experience with simply the mechanics of a 3D Platformer and does well to show off the graphical fidelity that can be accomplished with the PlayStation 4. Artistically this game is vibrant and colorful. Story-wise it’s interesting and yet universal for a wide spectrum of ages and personalities to find enjoyable. But most importantly the gameplay of Knack brings back the feel of old school gaming in a new school format of much higher quality than ever before made possible. Japan Studio, Mark Cerny, and Sony have put together what I consider to be the best 3D Platformer out right now." (Knack, PS4)
Probably would be forgotten (or missed) if not for being a launch game. Despite some of the reviews for this game complaining about its difficulty the game was fun and if they can tweak a few things could make for a fun sequel.
I don't think I'd recommend it as a 60$ purchase but is certainly worth a rental.