Saizeriya is affordable and frequented by families with kids, but no play area.
Restaurants with play areas:
1. Marche (suntec, somerset)
2. Kith Cafe (Marina sq) - not sure if closed
3. Buffet town (raffles city)
4. Hai Di Lao (all outlets) - supervised play area
5. Ikea - supervised drop-off play area located at store entrance but require minimum height and subjected to availability; Cafe has play area too