Let me preface by saying that Marie's is likely a great place to eat and socialize for the less adventurous traveler. If you typically visit All-Inclusives and upscale hotels, Marie's is likely perfect. If you, like us seek out hole in the wall, back alley eateries where people exclusively speak the local language and other Westerners are a rare sight, look elsewhere.
I don't even remember what we ordered...some kind of seafood dish that was adequately prepared and nicely presented, but not memorable. What I do remember is that it was the most expensive ticket that we had in our week in CR.
Marie's is at an open air, thatched roof area inland of the sea but right in the middle of Playa Flamingos tourist center, making it convenient for almost anyone staying in the area. The atmosphere was nice but obviously influenced by money and lacked the local flare that we loved about so many of the open air beach restaurants.
If staying in Playa Flamingo and looking for low key local, look elsewhere.