Hexen: Beyond Heretic

The Good
The game itself was pretty good, but the additions that Raven made to id Tech 1 for this game are what really makes the game shine, compared to all the other games based on the DOOM code.

Level design, and the ability to teleport between levels, helped make the world of Hexen feel much more realistic and immersive, compared to its predecessor Heretic. While every so often you reach a point where you can't go back again (something shared even with the most modern 3D shooters), this was new at the time.

Another modification that made this game special in its class were doors that could move side to side or swing. While the original DOOM code offered "sectors" with ceilings and floors that could rise or fall, Hexen introduced true door motion to the id Tech 1 engine, allowing for doors in-game that can swing or slide.

Last, and certainly not least, was the ability to script level and game events. Pretty much every game allows for some level of scripting in game content these days. At the time, it was a revelation.

The Bad
Monsters could have been a lot smarter. And those flaming birds were a real pain, especially in flocks. You could quickly waste all your ammo on killing those things.

The Bottom Line
It's a classic first person shooter, and while great in its original version, these days it would be better to play through one of the many available source ports.