With a couple of exceptions, there's not lots of great food in the Goose Rocks/ Biddeford Pool area - or in Kennebunkport proper, for that matter. Having said that, here's a list off the top of my head:
Order lobsters and steamer to bring back to the beach at Wolfe's on Rt 9 near the K'port/ Biddeford line. She used to steam them for you, but I think they have stopped that service.
Nunan's, Rt. 9, Cape Porpoise for lobster, steamers.
There is also a clam shack on the Cape porpoise pier
I hear Pier 77, also on the pier in Cape Porpoise, is OK.
Bradbury bros. market in cape porpoise has really nice meat selection.
The Tide's Inn By the Sea, on Goose Rocks Beach, food decent. Go for atmosphere, view, friendly service (worked there summers as a kid and it's still the same owners) and a great pub.
Mia's right off rt. 1 in Saco (they also offer brunch)
There will also be a new brewpub in Saco, sometime soon.
The Green Heron on Ocean Ave, K'port, for breakfast.
Wayfarer in cape Porpoise supposed to be good for breakfast
The Cheese Iron on rt 1 in Scarborough for a really great selection of cheeses.
Arrows in Ogunquit for fine dining...but I highly recommend driving up to Portland to get some REALLY good food.