Check out play house and cafe at thurnscoe. It's catered for children under 5. They have role play area too. But feels so much safer because there isn't any big slides
Charley’s play barn at marsh gate Doncaster has jsut opened
There's one called Little Town of Play near Mexborough which is really good! Also Play Valley Doncaster has a role play street as part of it too, and a good soft play for toddlers. Boston Park Farm is nice for a few hours, you can get hands on with feeding the animals etc and they do toddlers 'mini farmer' mornings.