Shoe polish contains waxes and other ingredients that shoe cream does not. Shoe cream is more of a dye containg leather conditioner so won't produce the luster and shine of the polish. Probably better than shoe polish in most cases. Just use a utensil to stir up the long unused shoe cream... it'll be just fine.
Here in the western U.S., we use an undyed version of shoe cream for treating leather goods, such as the tops of our well worn boots, horse halters, bridles and saddles...