Not much new, but still fun!
There's a lot of recycled material from the previous games, but the levels are bigger and have more stuff to collect. The gameplay is pretty much the same with the exception of a few of new things and a few new game types, such as rolling up hot things to get your Katamari hot without rolling up cold items that will cool it down. And let me tell you, this game is noticeably harder than the previous games because of the time constraints! Almost every level seems like there just isn't enough time to make it through. And even when you do make it through, it's very hard to impress the Kings this time around! The King of the Cosmos seems to lack his carefree-ness in this one but has heighted his arrogance, which is unfortunate. Robo-King is a pessimist and lacks self-esteem, but feels like it's easier to relate to him. And without giving any of the story away (of what little there is), it's sucks how it ends for him! I ended up caring for Robo-King and it's just this unfeeling ending towards him!! :'( (Oh by the way, the cut scenes in this one are just out there...)
There's still two-player coop & battle. I never really enjoyed playing those modes so I won't say much about them. There's the addition of trophies in this one and there's also online rankings for anyone who feels the need to impress.
Visuals have a nice cel-shading to them and you can also change them to what you remember in the previous games. It's a shame that all of the King's levels are pretty colorless because of his lost memory. Half of the game is like this and even though it's still fun rolling up stuff in these levels, it gets somewhat uninspiring. It's a neat idea to have things gradually color-up as you collect their identical items, but there are so many things to collect, color just doesn't seem to stay long enough. It would have been nice to at least have the levels completely colored when you go back to play them! The Robo-King's levels however do stay colored and are visually appealing, even more so with the cel-shading. There are some visual pop-ups here and there, the camera is sometimes a problem and the framerate can slow down at times, but all in all the visuals are smooth working.
The music & sound are still good with the boops and beeps and there are some cool remixes of old tunes.
Though it is noticeably harder than the others (or maybe it just seems that way because of the new scoring system and the Kings comments) and some things seem to be left out or not exactly put together well, Katamari Forever is a fun game to play and at least the very least a good rental.