There's nothing wrong with the Sun Wheel. Those cars simply fall forward or backwards with gravity giving you the sensation of being pushed off a skyscraper. Then they rock while you fall and change directions to help ensure you get motion sickness if you are so inclined.
It's a great ride to bring a date on, because with luck, the girl will find it thrilling and associate that with you. Or she might throw up, which wouldn't bode well for the future of the relationship.
My only complaint is that it's a simple fair ride with no real theme. I am glad it's a bit more than just a simple ferris wheel.