Fahrenheit isn't a remarkable game, to be honest. One of the last major FMV titles on the Sega CD, it saw release in the US, Japan, and Europe. Gameplay consists of watching a movie play out, and then much like a Dragon's Lair, you are given a directional prompt at certain points to navigate a burning building. Going down the wrong way often just wastes time, in the form of your oxygen supply. The instruction manual has floor plans for each of the stages to help you ahead of time since otherwise you're running around the buildings randomly. Compared to its other FMV game contemporaries, it would be just another one of those types of games and otherwise forgotten. And in Japan and Europe, that's pretty much it, another Sega CD FMV game.
In the US, however, it was a bit different. A handful of games were released during the 32X era that took advantage of both the CD and 32X add-ons simultaneously. Unfortunately, most of them were ports of existing Sega CD games (Night Trap, Corpse Killer, Slam City with Scottie Pippin, Supreme Warrior). Those four games ended up getting released in the US and in Europe, but Japan didn't get any of the 32X CD combo games. One game, Surgical Strike, was due to be released for the 32X CD combo unit, but that version ended up getting cancelled, setting for a standard CD release...or at least, that was what was supposed to happen, until it was discovered that Brazil got the 32X CD version. But that's another topic. Fahrenheit also ended up getting released in Europe and Japan as a standard CD release; however, the 32X CD version was exclusive to the US.
The thing about those 32X CD combo games in the US is that the packaging was a hard cardboard longboxes that folded open and closed, using the 32X yellow stripe design, with "SEGA CD 32X" instead of "SEGA 32X." Digital Pictures, the owners of those various FMV CD games, had also used this style of longbox for their re-release of Night Trap on the Sega CD sometime after their deal with Sega had expired. Fahrenheit, meanwhile, ended up using the plastic longboxes that most of their other CD releases used. The second picture I enclosed shows what it looked like inside the longbox. The plastic disc holder on the left side is interesting because it is rigged up in a way that you can just slide the manual out without removing that plastic disc holder tray.
The split blue/yellow stripe design on the cover art is unique to this game. In the later years of the Genesis in the US, games started showing up with a more unified cover art design to make it more explicit that the game you were purchasing was for the right platform. The red striped pattern was for Genesis games, blue striped for CD games, and yellow for 32X (and in the case of the handful of Digital Pictures releases, 32X CD). I suppose in theory, this half blue/half yellow pattern could've been used for any other games that included the CD and the 32X CD version.
In fact, this is the main reason Fahrenheit is unique among CD games, even among the 32X CD games. The game includes both the standard CD version and the 32X enhanced version, the only game to do so. With the Digital Pictures 32X CD ports, those only worked if you had the CD and 32X combined to use it. Fahrenheit include both versions in one package. Not sure if it was ever explained why it was done like this, but my theory is that they either thought releasing both versions of the game as individual products wasn't going to do well for sales of the 32X CD version, or that they hoped that Sega CD owners who were still on the fence about getting a 32X could buy the game now and then maybe think about getting a 32X later down the road to play that enhanced version.
The game comes in two CDs. Each CD contains the full game. The first CD is the standard CD release, and you can just play that version normally (if you don't have a 32X hooked up). The second CD is the 32X enhanced version. Presumably, it needed a whole other CD to take advantage of whatever programming was needed to get it to talk to the 32X add-on, as well as higher quality video assets. Now, somebody at Sega must have thought that folks would buy the game, and then try and sell one version or the other away to save cash, so in a bit of weird "anti-used-game-sale" tech, in order to play the 32X CD version, the standard CD version also functions as a "key disc" that you need to insert first, after which the game will tell you to swap CDs to the second.
And that's one of the weirder things about this setup. You see, if you have the entire Sega Genesis CD 32X combo unit hooked up, loading up that first CD will always ask you to swap the CD. Something in the programming of the way the first CD is rigged up is that it'll check for the 32X, and if it sees that the 32X is connected, it'll inform you to insert the second disc. If you have the entire combination unit, and wanted to play the standard Sega CD release for whatever reason, such as to do a comparison between the versions or because you really don't care about disc swapping and want to just get to the game, well then too bad. You either need to swap the disc when prompted or remove the 32X, your choice.
As for differences between the CD and 32X CD versions of the game? Not too much. Gameplay is the same between the two. The 32X CD version has better video quality and more colors displayed than the standard CD version. However, for some reason, the audio quality on the 32X CD version takes a hit compared to the standard CD version. Not sure why this is the case. My assumption is that the higher quality video assets took up more space than was expected, so they had to compress the audio a bit more to get it all to fit.
Asides from the way they marketed and packaged the game and the way the two versions work with one another, the game is...well, it's an FMV game where you choose a direction to push when prompted. I was always more interested in how unique it was as an actual product and how the game functions depending on your hardware configuration.