walkway over the hudson
Rossi's is amazing, but they're closed on Sundays.
It's not within walking distance, but Formosa Cuisine (near Marist, around the left side of the strip mall) is great and very reasonable.
You might want to park on the Highland side (it's free) because it's very difficult to get street parking in Poughkeepsie on weekends.
11 Marist Drive, Poughkeepsie, NY 12601