Despite its quirky atmosphere, Katamari Forever is too bland of a game to warrant more than a single-play through.
You play as The Prince and are responsible for rolling every object you possibly can into giant balls called "Katamaris." The point of which is to help both the King of the Cosmos and Roboking, his evil robot clone, rebuild the universe. Essentially the King of the Cosmos has lost all his memory about the galaxy while the Roboking simultaneously went on a destructive rampage where he blew up all the stars in the sky. Yes, the story is really just an excuse to break into some random person's house, garden or other creative location in order to create these Katamaris and consequently relocate their possessions to being stars in the sky.
The two kings, who act as your 'mission givers', task you with collecting certain types of Katamaris. Sometimes it will have to be rich, other times delicious, and occasionally it'll just have to be a certain size, but all in all you're still doing the same thing throughout each of the well designed 34 single-player levels. In every case you start out pushing a relatively small Katamari, and you progressively build it up by collecting bigger and bigger items often for no reason other than collecting even more items. While this is fun for a little while, the core gameplay is rather bland as you primarily control your Katamari with the sometimes frustratingly unresponsive two analog sticks. Consequently you will find yourself falling off ledges, and missing objects due to these imprecise controls.
In the game designers' defense they did seek to compensate for this lack of control by including the Prince Hop which, as the name indicates, allows The Prince to jump super-humanly into the air with his giant Katamari attached. Further, they added the Vacuum Bonus feature which occasionally comes into play and alters the pace of the game by allowing The Prince to suck up nearby objects into his Katamari whenever a certain number of hearts are collected within a given level. Although both the Prince Hop and the 'Vacuum Bonus' are welcome additions, they really do not affect the game all that much meaning that the six to seven hour campaign doesn't really entice users, through gameplay, to complete its half-amusing, half-ridiculous story.
Luckily there is incentive to complete the game through other means as Katamari Forever is quite focused on collecting various items ranging from the new objects available in every level to the hidden presents, and even your lost cousins that almost become stars. These collections stand to do more than make you feel good as you can unlock photos, videos and the ability to play as your cousins in any level! Sadly, it appears like the apple doesn't fall too far from the tree as these cousins only differ from The Prince in terms of physical appearance. Nevertheless there are many trophies, photos, videos, presents, and cousins to warrant at least a single play through of each available level.
Additionally, unlockable mini-games and game modes have been included in Katamari Forever. These mini-games are often more creative than the main story levels in which they are included and provide an interesting experience for gamers. In one case if you fail a level you are tasked with the difficult mission of avoiding lighting strikes in order to regain your majesty's graces. These are fun diversions, but really don't have enough to them to merit more than a few minutes of play. On the other hand, the unlockable game modes, such as Katamari Drive where you move at ridiculously high speeds, provide a tad bit more chaotic fun for all gamers.
Graphically, this game stands on its head. The environments are large, colourful and are more than pleasant to look at. The destruction you cause leaves a distinct mark on the terrain, and the detail of every object will have you gawking at your screen. The sound compliments this visual environment by providing appropriately bizarre tunes that vary depending on your location. Anytime you replay a level you may choose the track you would like to hear, but more often than not the original one is most appropriate for any given level.
Beyond that, the game designers ought to be applauded for creating a gamer-friendly atmosphere as they incorporate the old so well with the sort-of new. The Roboking's missions occur in "new levels," only three of which are completely new, while the King of the Cosmos' missions occur in fan favourites from past entries in the series. While this doesn't hamper new gamers' ability to succeed, it provides a benefit to those loyal Katamari builders.
Further amusement may be found in the local multiplayer option that offers two distinct modes of play. The first of which is a versus mode where the goal is to make the biggest Katamari. While a human opponent provides a much needed challenge to an otherwise easy game, it isn't too engaging. The second, and arguably more enjoyable mode, has you and your partner roll the same Katamari which proves to be hilariously difficult to do. There is no online play, but that omission is easily overlooked as it would add very little value to the game.
In short Katamari Forever, a game driven on its unlockables, provides a remarkable and quirky atmosphere that stands to shadow some of the games flaws. However it is too bland of a game to warrant more than a single-play through.