We were at GWL Concord over Thanksgiving, our first trip there. The kiddos LOVED the water park, though its smaller than the Grapevine TX waterpark at GWL by a lot!
We actually had made our reservation on a MEAL promo, wasn't free, but was a good meal deal we thought. The website makes it seams like there are multiple dining options at GWL but there are not. "Loose Moose Cottage" and "Camp Critter Bar & Grill" are the same restaurant. Just a different name at different times of the day (and perhaps where you are seated). The food was pretty lame, especially for the pricing. After the first night, we wish we wouldn't have done the promo then we could've hopped in the car and gone someplace with better food. We ate there only because it was prepaid, we certainly wouldn't do it again.
There is a Dunkin Donuts, a pizza hut express (which is pretty expensive), and then a bakery/sweets place, and then a snack bar in the waterpark area. Snack bar is probably the best options there, just the basics, but not cheap either-- if we go again, we'll stick with bringing breakfast or grabbing at Dunkin Donuts, snack bar for lunch (or bring our own), then we'll go out somewhere else for dinner. There are lots of options just outside the lodge/within a mile or so.