Alright, this review might be a little bit biased or flawed, because this is only the second review i've written, ever, but here goes.
Story: 7/10 Nothing special here. But what can you expect from a Kirby game? Dreamland is in trouble again and Kirby comes to the rescue. Yeah...
Gameplay: 9/10 The power combination is perfect. Basically, there are 7 powers. But, when you combine them with another, it becomes a totally new power. It's so fun to experiment with all the different powers. The combined powers go from light saber (ohmygawd) to exploding shiriken to curling rock to refridgerator. Besides the powers, the gameplay is awesome. Fast-pased Kirby action. Lots of unique enemies and bosses. The game is a little short, though. Only 6 worlds and one hidden one. Also, you can play as King DeDeDe in some segments. He's awesome.
Sound: 8.5/10 The soundtrack is actually really good. Most of the songs are memorable and catchy. I've had this one stuck in my head for the past week:
Graphics: 9/10 The graphics looked good back then, and they still look good now. It was one of the most impressive-looking games of the day. The levels and characters are incredibly detailed.
Replayability: 8/10 Once you beat the game, you can go back to levels to find the remainder of the Crystal Shards, which, once all of them are found, will unlock the hidden final world, where you fight Zero 2 and his incredibly awesome boss theme. Also, the game is very fun to replay.