If there were 3.5 stars, I would rate it there, but it definitely doesn't deserve 4+.
For those who don't know what Knack is, it's basically a poorly written version of Optimus Prime from Transformers with mediocre gameplay execution similar to the Lego Games.
As for the positives of this particular title, it has a decent amount of content with 10-15 hours for the main story and 20-25 hours if someone wants to platinum it. Its biggest advantage is that it allows for full co-op play with two players, but it can also be continued with just one player. So if two players start the story and one leaves, the game doesn't force you to start from the beginning. Additionally, once it's completed, through the Chapter Select, you can play all the sections either with one or two players, regardless of whether it was completed solo or in co-op. The game offers a variety of elements such as puzzles, platforming, and a large skill tree that gradually unlocks. Unfortunately, this is where the positive aspects end.
Knack has one of the worst level designs of the modern era. Initially, all the levels look the same. You could be 3-4 rooms ahead and feel like you're experiencing deja vu because everything is copy-pasted. The secret passages that hide treasures are almost identical to regular walls, and those, in turn, are the same as the invisible walls of the game (the areas that define the end of a game and you don't have access to them). This is the biggest negative aspect because the repetition breaks your mind and bones. You have to press square 500 times, go through a loop 1000 times, watch a cutscene 10000 times. These are done to hide loading times, but when you encounter more of these in Knack compared to masterpieces like Uncharted, Last of Us, God of War, and GTA, then something has gone wrong. Repetition is found everywhere in the puzzles, battles, enemies, and movements. Basically, everything you see in the first hour of the game, you will see again and again in the rest. The combat system is mediocre, as the game has no idea how to balance the difficulty levels, either your enemies are ridiculously weak and die instantly with one hit, or they constantly spam their attacks. One thing is for sure, the large skill tree and most of the moves you learn are useless, as the most effective move is the air kick, which doesn't even need to be unlocked and can be used from the beginning, even though the game never shows it to you. The problematic combat system is completely exposed in the highest difficulty, where you see how bad the parry and dodge are compared to the enemies' attacks. Additionally, there are an excessive number of collectibles, with 100 chests hidden with parts and around 1000 relics scattered in various places. These, combined with the continuously copy-pasted sections, make you feel like you're playing the same part over and over again. A REAL NIGHTMARE. Also, the camera in Knack is mediocre for most of the game and disappointing in the two-player section. Finally, the platforming is tragic as the game executes the jumps almost automatically to avoid being difficult. However, in doing so, it sabotages itself by canceling the double jump and hover abilities. If you actually try to do proper platforming, you will simply die.
As for the co-op, which is also its strong selling point, the feelings are mixed. In this case, the ability to play with two players theoretically gives a uniform distribution of roles and powers to the players, but only on the surface. Essentially, the enemies are much more aggressive towards player 1 (who is always the red Knack), ignoring the other player. The game has a teleportation system so that no player is left behind. This creates a situation where one player can do everything while the other simply teleports next to them. The bad camera makes it necessary for one player to pass the difficult parts, otherwise you can't tell who is who and both players end up dying. The teleportation system negatively affects the ability to find secrets or explore the area better, as if the players move away, the game automatically teleports you to the player closest to the next area and you may not be able to go back since there will most likely be a cutscene. Also, in several points, you can't see or progress (especially when you become small) if the other player is not right next to you! In conclusion, Knack is a game with specific advantages but also obvious disadvantages, yet it is not bad compared to its predecessor. I believe that many of the negatives will be overlooked or disregarded by people aged 8-14. The low difficulty level, easy puzzles, and vibrant colors will convince them. It is also a good choice for an experienced gamer who wants to introduce a younger sibling, child, etc. The fact that player 2 can never be a serious obstacle helps in this area. Although there are very few couch co-op options on the PS4, Knack is a good choice only with this mindset. I tried and got opinions from many friends and acquaintances about the game by playing with them, but unfortunately, only my younger sister (age 10) was convinced.

P.S. The game Knack, as well as Knack 2, were created purely out of obligation. Marc Cerny, who is responsible for the creation and design of Sony's consoles (specifically the Playstation), set a condition for the realization of this title despite the tragic reception of the first one. Unfortunately, it is clear in this duology that it is completely different to work as a consultant on a game than to have to create it from scratch!