My kids went to a co-op play-based nursery school. They didn't learn their letters or how to read there. They learned how to be social beings, listen to adults other than their own parents, share and take turns, put toys away, sit in a circle to listen to a story, sing and take turns talking about their weekend, birthday, new sibs, vacations, holidays, etc.
They were also exposed to a rich variety of creative materials - clay, paint, sand, dress-up clothes - and play equipment - slides, swings, twizzlers, climbing structures.