i've played up to the first 3 world and i pretty much agree with what was already said
the level do have a nice personality to them,there is a dinosaur level,a cake level,a toy level,a music level but they are all so dull to traverse,there are no stuff to dodge,no jumps to make,barely any enemy to fight and the 3 hidden treasure are hidden in the same sense that this post is hidden in the fact that you have to scroll down to read it,it's really a shame
anyway as it was said,you can't die,ever,when you get hit,you lose beads which dictate your ranking when you finish the level,what wasn't said is that you lose beads a-la sonic rings so it's pretty easy to get all your lost beads back unless they get stuck into an hard to reach place
in some levels kirby transform into something near the end,it works pretty much as yoshi island,heck some transformation are even the same,this adds a little variety but it really doesn't help the game too much,examples encountered so far
spoiler (click to show/hide)
Tank - kirby drives a giant missile firing tank
UFO - Kirby can fly around,suck enemy and release electricity which destroy everything
Fire Truck - kirby has a water pump he can use to turn off fire
Digger - kirby digs around dirty
Racing Truck - makes kirby go faster,used in race segments
Train - Draw tracks with the wiimote and kirby follow them
my biggest disappointment is the music,to me it just sounds like generic piano music
but the bosses are good,especialy the third one
spoiler (click to show/hide)
it was a giant pumpkin magician,the whole fight plays in front of an audience of waddle dee and he spins a giant roulette,3 hats and he hides in his giant magician hat and kirby has to find him,3 cards and he throws magic card,3 ropes and he straps kirby to a giant bomb and kirby has to waggle himself free

,3 mantle and he makes bomb appear out of nowhere
anyway there are extra modes that you can unlock,stuff like "find the 5 hidden stars" or "get 200 Beads in under a minute!" but they take place in levels you already traversed,they are already dull enough the first time,doing them twice is overkill! to make it worse all you get for clearing these extra modes are wallpaper to put in your special room,what is this animal crossing?
apparently this game was made by the same guy who made wario land shake it and it makes sense,since "THE GRAPHICS ARE AWESOME,THE BOSS ARE AWESOME BUT THE REST OF THE GAME SUCKS" was pretty much what i tought of it