Kung Fu (1985, arcade name Kung-Fu Master) was one of the early NES games, and it's a foundational beat-'em-up. You're Thomas, climbing five floors of a tower to rescue Sylvia from Mr. X, punching and kicking through waves of grippers, knife-throwers, and henchmen.

It's simple — move right, hit things, fight the boss, climb — but the responsive controls and steadily ramping difficulty made it endlessly playable, and it laid groundwork the entire side-scrolling action genre would build on.

For a launch-window cartridge, it holds up shockingly well. Sometimes simple and tight beats big and complicated.