We have been there twice, and will go again within the next few years. Here is a summary that I posted for someone else a few weeks ago:
Flat, good-sized pitches. Large pool for proper swimming. Straight and curly slides. Magic river. Bar, games, mini-golf, table tennis etc. Peaceful. One central block, always clean.
About 3 miles from sandy beach in quiet cove (Les Quatre Vents). Many other good beaches within 10 miles. It is 18 miles west of St Malo.
It's a busy site, but very good. Matignon is very sweet, and has a weekly market. There are several seaside towns within easy reach.