Read the original Co-Op Classics article
I'm always thrilled by early examples of cooperative gameplay, and Wizard of Wor is one of the earliest. A combination maze/shooter, the game was notable for synthesized voice and moody, atmospheric music as well as simultaneous two-player gameplay. A great example of the wide-open design space of the Golden Age that allowed for so much creativity and innovation in just a few short years. Also, the game is really difficult so don't make too much fun of my non-existent Worrior skills!