This can be as little or as much as the participants desire, and can include the mannerisms, behavior, and look of said animal.
Unsurprisingly, with a growing trend for such character traits as sensitivity, emotional unavailability and not having children, house cat ownership among guys.
Other aspects that can be incorporated into kitten play, depending on how serious into it you and your partner are, is things like having cat bowls for food and water, using a litter box or having your own cat bed modified sizing is probably needed.