"Playroom - LOVE THIS! Even if you only did this in a one-story height basement it would be pretty darn cute. Paint the ceiling, building the little closet "stores" and install mini doors and windows." This is such a cute idea!!.
A few adjustments (switch the rug out for a grass rug the color of sand and switch the balls out for sailcloth pillows, shells, oars, sailboats, bouys, or stuffed animal Sea creatures), and you've got yourself the perfect nautical kids room.