The big red wheel that is the Riesenrad dominates over the park. People of all ages will enjoy the ride and views, but those old enough to appreciate that the Riesenrad is the oldest ferris wheel in the world may take a bit more away from the experience of riding it.
This park has everything any other typical amusement park has: rollercoasters galore, game machines, haunted house. But the ride that really stood out for me was one tucked away at the back of the park. While I can't recall the ride's name, it has a huge arm that spins around with 4 seats on either end of it.... Well worth the €8 fee to enter.
Those slightly more game might take on the bungee rocket which catapults you to about 15 stories high before bouncing you slowly back to earth.
There is plenty of grass around the outskirts of the park, and it is well served by nearby shops. It might be a good thing to play in the afternoon, then retire to the grass for an early evening picnic before taking to the Reisenrad (€13? adults, about half this for children) to see the sunset and some stunning Viennese views at dusk. The ferris wheel takes about 30 mins to complete its cycle, so factor that into your schedule.
One could quite easily spend half a day unwinding here in the sun and enjoying the screams of those crazy enough to take on the most challenging rides.