As much as I hate to rate an episode of TOS poorly, there is really very little to recommend The Apple. The plot is yet another version of Patterns of Force, Return of the Archons, Shore Leave. The chief conflict is between an Enterprise landing party and the local God, Vaal (a supercomputer which runs the planet on which the party has landed). Inexplicably, explosive rocks, targeted lightning, and killer plants also inhabit this planet. Of course, the humanoid population are a group of large young-looking, white haired, orange skinned, immortals who are literally and figuratively the children of Vaal.
Redshirts die in new and original ways. Scotty gets fired. And writer Max Ehrlich also provides some of the strangest and least appropriate attempts at humor TOS ever had. One thing that does come across well in the mediocre script is the desperation and indecision of the landing party. Unfortunately, at times, Kirk become uncharacteristically whiney.
Joe Pevney's direction for this episode is decidedly pedestrian. Surprising given Pevney's track record (director of the great Trouble with Tribbles, Devil in the Dark, Amok Time, Wolf in the Fold, etc), and the budgetary limits on the sets, props and effects are very apparent.
Avoid unless you are a fan.