I really didn't enjoy it. There are several things in this one that I didn't like, even though some of these are purely subjective. I can easily see how people would really like or love this game, though.
I think what I didn't like the most was the level design. While I think the use of Kirby's friends is a good idea, I found myself not liking it very much. Most of the time I preferred to play as Kirby because I didn't struggle so much to walk around with him.
Several times through the game, there are situations where after crossing a door, you have to react very quickly, because either an enemy is dropping on you, or because you're on a disappearing block that will make you fall into spikes. That's kind of scummy in my opinion, but it wouldn't be as big as an issue if they had implemented the double tap to run, like in Kirby's Adventure.
Compared to the previous game, the final boss didn't do much for me.
And Dark Castle 6 can choke on a cactus.