It's not as bad as people say it is, but it isn't especially good either.
Bionicle features racing, fighting, collecting and flying. With all of these different things to do, you should find atleast one thing fun here. Personally, it isn't bad.
If you've played and beaten all of your other games too many times, then this game is good because it's something different, but that's the only time you'll get a lot of enjoyment out of it.
True, the graphics are bad and the gameplay isn't top notch, but it's better than Jimmy Neutron. Maybe if you're a fan of the Lego sets you'll love this game, but if you don't care for the Lego sets, then this game isn't going to make you like them anymore.
Pros: Great for fans of the Lego series. There are a lot of different things to do in the game, even if they aren't super fun. Some of the levels are cool.
Cons: Bad graphics. The gameplay isn't bad, but it's not special. The voice acting doesn't compare to the movie. Some boss fights are interesting, but most of them are lame and repetetive.