Any works of media are copyrighted--music, voice, artwork, photos, code, etc.
Trademarks protect company/product names, logos, catch phrases, and other related artwork designs to some degree.
Unique mechanisms or methods of producing something can be patented. However, by this point, most of the pinball patents have run out and entered the public domain. Patents give the author exclusive rights of use for a period 20 years.
Objects that are built/manufactured for use generally can't be copyrighted, unless it's classified as an "artistic work", such as a mask or sculpture. If the object itself can't be copyrighted/patented, any artwork placed on it still can be copyrighted.
