Tron
Your user can't help you now, my little program!
Not only was Tron a landmark fashion event for fans of skin-tight circuitry wear, the accompanying arcade game was probably the first overwhelmingly successful film license. Indeed, it's rumoured that the game took more money than the film itself. An early exponent of sub-games based on key cinematic scenes - later to become the standard (and extremely tired) method of movie-conversion - the game was a genre-shaping release.
Tron occupies a niche place in history. Its glorious art design and execution were bolstered by the fervour of the arcades, giving it an unusual opulence for the period. Its cultish appeal lies with those who were there, who experienced that "era," and crave a chance to relive those days.
The title's four sections provide a stern challenge, requiring a sustained battle through light cycles, tank patrols, "Master Control Program" attacks and spider hordes. Moderate aid is available through the designated control method, a large, Gorf-like joystick for movement and spinner for aiming; but that's about the only help you'll get, and the precision must be mastered in order to survive.
Whilst the light cycle segment of the film was probably the most exciting (and most often duplicated by videogames), this early arcade rendering is somewhat less impressive, due to the fact the enemy cycles always follow the same pattern. There's little skill involved, bar working out how to beat them on each level. In comparison, the other three sections require greater tactical awareness and defter adaptation to the surroundings.
Anyone too young to have seen the original film is advised to rectify that before playing the game; if only to observe how a proper license is done. For the Tron-veterans, the game is an impressive C64 gateway to a glorious point in their past. Just try not to get trapped inside.