It was originally supposed to be a sequel to Heretic (an early work title was Heretic 2), but Hexen (1995-10-30) turned out to be an independent game, though set in the same universe. They tought the Doom engine a few new tricks, like dead leaves blowing in the wind, there is more interaction with the environment, albeit restricted to destruction. The legacy of Black Crypt is felt stronger in Hexen. You can choose between three character classes (Fighter, Mage, Cleric), puzzles are tougher and more important for gameplay. On the whole, there is more difference between Heretic and Hexen than there is between Doom and Heretic.
Unfortunately, since it uses the Doom engine, Hexen runs in VGA only, while the graphics are simply not fit to be displayed at this resolution. In the first scene, it is difficult to make anything out among this fog of grey and brown pixels. Later third-party enhancements like Korax have taken care of that.
I found some pre-release screenshots of Hexen, which I have inlined into a HTMLized version of the readme file that accompanied them (257kB). Technically, these are not thumbnails, they are the original size, but if you click on them, you will get a version that's blown-up to 640×480 via HTML.
I don't know much about this Windows version. Like the one for the Macintosh, it's supposed to render at 640×480, but I've never actually seen such a screenshot. If you download the Windows demo from the id site, what you actually get is the original DOS demo from 1995 that you can download below.
Raven called this a demo, not a shareware version. The difference is usually that savegames from the demo won't work in the full version, or that levels are different. I do not know if either is the case here. It is limited to four levels, but it is fully multiplayer capable, both cooperative and deathmatch. I guess it's more shareware than a demo. Maybe, by 1995, shareware had become associated with mediocre programs, and therefore Raven (or id, who published the game) avoided the term.
As was to be expected, the Macintosh version renders at higher resolutions, up to 640×480. I don't know if it's PPC only, but judging from my Wolfenstein 3D experiences I'd say you'll need one anyway for enjoyable play.
To apply this patch, unzip the archive anywhere, it doesn't matter where, and start INSTALL.BAT. You will probably asked for the location of HEXEN.EXE (unless it's in C:\HEXEN, I guess). The patch will then check the date stamp, and if it does not find what it is looking for, it will abort. You can only patch a completely unmodified Hexen install. If the time stamp matches, you will be asked where you want to install to, now you have to enter the Hexen directory again.
The 1.1 patch is prerequisite for the Korax Mod, which is the main reason I put it up here. Otherwise, it just fixes a few bugs and adds 8-player IPX network support, previously the maximum was four.
