I recently held my son's birthday party here and he had an amazing time. We booked it in the morning period, had two courts to ourselves and they had sand toys for the kids. As well, we had an animator, who was great in watching the kids from throwing sand at each other, and getting them to participate in the games. A great location and I would go back for sure!
Note: The entrance to this location is slightly deceiving to the actual address. The entrance is on Rue de Square Gallery at the very end near the canal. You enter near the gates and you go through the pub entrance door.
This fall (2014) they will start holding a drop in program for kids so they can play in the sand. I will go back for sure since its nice fun for kids.