Knack’s main mechanic is the titular character’s ability to absorb relics and become larger and stronger versions of himself. When the game starts, and actually at the start of each of the game’s locations, Knack is small and has a fairly short lifebar. As you make your way through the levels, you will collect relics and as you grow to the different versions of Knack, you can not only deal out more damage, but the longer health bar means you can take more attacks. At least that’s how the game appears on the surface.
Knack’s levels actually consists of a very linear map filled with narrow passageways that frequently open into clearings filled with enemies. As a result, the gameplay experience means that you walk into an open area, or room, or cavern or whatever, and tackle the bad guys that populate that area. Once that’s done, you move on and find the next mini-arena. While you do feel like you get more powerful as you gain more relics, this is actually a trick based on the scale that changes as your character grows. In the end, you are pretty much always a few direct hits away from restarting at the last checkpoint, it’s just a matter of that damage being dealt by birds and bugs or massive mechs and ancient guardians.
Sure you feel like you can do more damage when you can take out an enemy with just one hit that previously took a lot of damage, but in reality, that enemy has just moved to a lower tier of opponent and something else has taken its place as the tough enemy that you have trouble getting past.
Much in the same way that Katamari is all about getting bigger and changing the scale of your perspective, Knack is all about scale as well, but where Katamari has you rolling over the same area over and over again to really sell you on the size increase, Knack just keeps pushing you into the next area. The result does make you feel like you are getting bigger, especially since you start climbing over buildings, but it just doesn’t have the same impact that Katamari has.
There are several points where Knack’s abilities get a little more interesting. Eventually, Knack learns that relics aren’t the only thing he can absorb. When he sucks up clear crystals, he can shed all his opaque relics and sneak past trip lasers. When he grabs ice, wood or metal scraps, he has an added layer of shields that will take damage before he does. Unfortunately, there isn’t really any strategy to these added abilities, it’s all very scripted. It isn’t like you get the ability to switch between Stealth and Ice Knack or anything like that. Once you are done with the stealth area, that ability is lost; once you don’t need the metal shields any more, it is gone. While these abilities are fun to play with while you have them, don’t grow too attached to them.