Great game if you want something that's quick but innovative. Give it a chance!
The graphics for the game are definitely better than mediocre. They do the job just fine. They don't look great though. The city levels and toy levels look brilliant, but cake and grass levels look pretty bland to be honest. The music of the game is good though. It's quirky, perfect for a game like this. They add the perfect atmosphere, and I never grew bored of them. The sounds like balls make can get a little annoying though, which is why I usually choose one that doesn't make noise. There's plenty of choice though!
The different balls add a lot to gameplay, as they all have different attributes. What do you want? Speed with less control, or mass with less speed. It what suits you to do your best. And then I get onto the multiplayer. To be honest, the main game is great, but multiplayer doesn't add much. It's just a race to complete it the fastest. It might have been better if both balls were on the same maze, and you control your ball instead of the maze. And you can bump each other out of the way!
As I say, there's always lots of secret levels and balls to unlock by completing levels fast. And if you try and get fast times, it does get exceedingly difficult. You cannot make mistakes at all and must always be going fast. But if you enjoy quick games, what you'll play in short bursts but won't get bored at, this is your game. Please don't expect Ocarina of Time type gaming though. You'll be disappointed!