Knack is one of those games got got hit-jobbed by most "professional" reviewers because its not of the typical mold of a blockbuster game made today.
Its is what it is- a fun acion brawler with a cartoony style, and simple controls, that provides a fun 10 hour campaign- the controls don't get more complex than run, jump, punch, and consumable "special moves". Yes, its linear, no there isn't multiplayer, and while the graphics are clean and 100% fine for the type of cartoony game it is, it far from "pushes" the PS4 graphically. So, it must be a 4/10, right review people?
Look, if you enjoiy the action/platformers of old- Crash Bandicoot, Spyro, etc. and learn for games from a simpler time before there was online MP, DLC, and everything needed to be a shooter, or an open sandbox, Knack is an entire worthy game to play. Plus its actually challenging- while there are patterns, enemies are agressive, have more than one attack pattern and you are always a hit or two from death, although frequent checkpoints keep things from being frustrating. It honestly was an 8/10 overall for me. Yes, its not the most ambitious game you'll play next to the latest EA/Ubisoft blockbuster game, but i had honest to goodness fun for the duration.