A perfect play room for a young kitten is a cardboard box. And cheap too!
Here is our kitten Bridget (named this as we rescued her on a bridge) with her toy du jour a big cardboard box with a ribbon stapled onto it and a wiffle ball stapled to the ribbon. She can bite, scratch and play to her heart's content!
The best part is the afterglow. After playing furiously, Bridget becomes very tired!