I've only been to the Italian restaurant "La Piazza" next to that fountain behind the hotel.
The food was excellent and made with fresh pasta. Prizes were also ok.
Some meals were more than enough, some could have been more. The waiter was amazing and we had so much fun we cried. (He told me he won't be there next year but the restaurant worthes a visite for the food anyway!)
The owner even came to the hotel on Saturday after closing to thank the chairman for the great guests we were.
Opening times are daily from 11 to 24. Sitting outside is possible.
On Sunday we had brunch at the Café Flair, right next to the McDonald's.
http://www.cafe-flair.de/They offer brunch on Sunday and holiday - very good food in lovely atmosphere for 7,90 Euro.
The mozarella-tomato-salad was yummy and they had very good cheese there.
Very good ice cream we had at the Rialto, next to the "other" huge shopping center Allee-Center in the Breiter Weg 19. Five Minutes to walk from the Hotel.
And best Doener I had since long time was at the Bingöl Grill in the City-Carré next to the hotel at the entrance to the Kaufland supermarket. Gosh, that was gooood!
The Asia Snack on the other side was also nice and offered good quality.