Let's start with the cover art. That amazing cover art.
Sadly, it was only for the Japanese edition of the game (the American release featuring something a little less exotic). But just look at it. It's like something you'd have seen hung on the walls of one of Saddam's palaces.
The Third World War was also interesting for the kind of game it was. The Sega CD saw plenty of FMV action games, and platformers, but one genre it didn't see much of were turn-based strategy games. Which The Third World War definitely was. Imagine a game of Risk that let you negotiate with other leaders as part of the actual mechanics, and which also allowed the player to tinker under the hood with the basics of things like their economy, and you're getting close to what TWW was trying to do.
While the game was severely limited in what it could do, mostly because the Sega CD and a control pad were hardly ideal for this type of experience, it was still a novel idea for a console game, and a brave thing to even attempt. If one of Paradox's modern "grand strategy" games on the PC went back in time twenty years, I bet it would look just like this.
In addition to the grand strategic stuff, TWW also included a rudimentary, isometric battle system that looked like Advance Wars joined forces with Populous.
Because of this, while it looks crude as hell in video form, for those who could get past the presentation and get a handle on all the stats and news tickers they'll often rate it one of, if not the best game for the ill-fated platform.