Whether you're stuck on a particular level you can't get through, or are just looking for that “Perfect” rating that eludes you, taking these hints to heart should definitely improve your game.
Be sure to read all of the text before each level. In many levels, you'll have to scroll through the text using an up-and-down “flick” gesture to read all of it.
The text is often humorous, but more importantly contains important advice from your personal coach, including exactly what you have to do to win a level. Each level can have different victory requirements; adjust your strategy accordingly.
Learning to control ball speed is an important skill. The computer AI is much better at handling ball speed than you are. To compensate, try to keep ball speeds low, until you've set up a good shot.
Think outside of the court. Often, the “straightforward” way to attack a level may not lead to success. If the computer's too fast to pass, try finding another way of earning points, or a goodie you can use to change the situation.
Don't always try to imitate the computer. The computer AI used to run the red paddle is very different than a human. It has reflexes that make new decisions every 3000ths of a second, must faster than you can. And the computer has limited paddle speed, whereas your paddle will move as fast as you can move your finger. So sometimes trying to copy the computer isn't a good idea. This is particularly true when it comes to handling positively charged balls (if you haven't seen 'em yet, you will!)
Grab the paddle from behind the net. Most beginners move the paddle by putting their finger right on top of it; that's fine, but it leaves the finger in the way so you can't see close to the paddle. But you can control the paddle from anywhere in the lower third of the iPhone/iPod touch display. Learn to control the paddle with your finger in the net area at the bottom of the screen, and you'll have better visibility. This is particularly important for dealing with positive balls.
Be patient. Don't expect to finish every level on the first try, or even the first dozen. When it gets frustrating, quit and try again tommorow. A fresh outlook and some time away from the game will often work wonders.
And remember, not everyone will be able to finish this game all the way to the end. Try not to take it personally...
Hints for completing individual levels are not available online, because we don't want to “spoil the fun” of discovering new levels as you progress through the game. But you can get hints from inside the game itself...we'll occasionally send out hints using the Neonatura News Network, so keep a look out!