This is the worst game I have ever played.
If you like fishing, go fishing in a pond with a kiddie rod. It would be more fun than this.
The game has you jerking around the controller whichever way, and you don't need to shake it any specific way to reel in the fish. All you really have to do is wave the controller around wildly and the fish will be reeled in. There's absolutely no difficulty and no variation in the game play. You cast the line by waving the controller, you wave the controller to hook a fish when it bites right after the lure hits the water, and you wave the controller for a lengthy amount of time while it gets reeled in. Rinse and repeat. If you catch the right amount of fish of the correct type, you finish a level. Done. Go on to the next level, where the above is repeated once again. When you finish a cup, you go on to the next difficulty level where the only real difference is in the amount of controller shaking you must do to reel in a fish.
In conclusion, if you find yourself with a copy, return it for a refund or use it as a frisby/coaster/whatever and get yourself a real fishing rod.