Although sometimes silly in terms of special effects and production values, this is a story genuinely well-told. I'd not call it a classic, but it is a great deal better than most other TV movies you'll run into. Just look at the cast with lots of great roles by those you wouldn't expect, with Ian Holm, Peter Ustinov, and Terence Stamp in unforgettable roles. Stamp especially channels the same intensity in his Zod role as the emotionless and seemingly indestructible villain. Ustinov plays campily as the comic relief (an honor he shares with Roddy) Kalif of Baghdad, and Marina Vlady is at her stunning best and outshines the bland love-interest princess in every scene. Even future Star Trek babe Marina Sirtis (Councellor Troi) has her debut here as a busty harem girl with maybe 1 or 2 short lines.
Perhaps the best aspect besides the wonderfully addictive orchestral musical score, has to be the weird and trippy atmosphere inside the evil cave that Prince Taj has to explore to find the diamond. This whole sequence is definitely the strongest point of the film and is one of the best scare-sequences I've seen. Lots of creepy blue lighting, evil whispering sounds, hallucinations, etc. VERY 70's! This, coupled with the extremely weird-looking giant green genie, make this a movie that you just can't miss if you're into escapist fantasy.