This game is great.
The story is really cute, nothing ground breaking of course. The characters are really likable. It's your typical 2D platformer. You start out with bare minimum of abilities. As you go along you get more and more abilities. From double jumping, to spinning under water, to transforming into a ghost, a dragon or a seal. The main game plays out with the face buttons. With the menu on the bottom being used with touch screen controls. The menu gets more features as the game goes on as well.
Each level has a lot of hidden chests, some levels also let you find extra mini-games or bonus levels. You earn pearls throughout your journey, which can be used to buy parts of outfits. When you get a full outfit and equip it you unlock a special outfit.
These outfits are only seen in the menu, but they're cute. You can also mix and match them. There is also multiplayer via local wifi. Multiplayer in some of the actual levels in the story, which allows for one player to control Starfy's little sister Starly. Who's smaller, has different abilities and is pink with a bow. And multiplayer in all of the 6 minigames, which goes up to 4 players and all of which use the touch screen for controls.
I didn't get a chance to play the Multiplayer personally. After you completely Starfy's adventure, you unlock a mini adventure for Starly. Which is nice.
It's a really great underrated DS game. It's packed full of content that easily makes it worth buying for anyone.