The GoodDescent left me cold, sad to say. A lot of people think it was the bee's knees, but at the time, and today, I didn't really appreciate it. Technically it's very impressive - proper 3d whizzing around on a 486 is nothing to sniff at - but otherwise it just doesn't seem to offer much in the way of fun or excitement. Still, lots of people seem to like it, so I assume it's just me.
The BadWhilst it was a technical feat, it lacked the character of Doom - the generic robot bad guys were boring, and the levels quickly became quite tedious and samey. Ironically, it didn't have the same variety, despite the 3d-ness.
The Bottom LineA groundbreaking fully-3d Doom-esque shooter, marred by repetition.