Visited here on a Sunday afternoon, had lunch while walking through Bally's casino.
We ordered a Cobb salad, half sandwich, two bowls of soup and drinks for $27, the service was friendly although was a little slow since the cafe was packed with people. Overall the food was good and filling. They do have specials on the menu and if you use your Total Rewards card, you will have a discount on certain menu items.
The cafe has limited hours and at the time I visited was only open for Breakfast and Lunch, closing at 2pm.
Overall, I would visit again, please keep in mind that this cafe does get busy but there are multiple dining options within Bally's to keep you satisfied. The Sidewalk Cafe is located between the escalator and the Tequila Bar.