ULTIMA UNDERWORLD / Origin / PC
When the conversation turns to pioneering first-person 3D games on the PC, Wolfenstein and DOOM inevitably will come up, but it's rarer to hear Ultima Underworld mentioned. But work on UW actually began long before that of Wolfenstein, and UW was actually ahead of DOOM in numerous respects (allowing you to jump, swim and fly, and having inclined surfaces and curving walls.)
The Avatar once again gets sucked into Brittania, this time he's plopped into the middle of a kidnapping of some Baron's daughter. In spite of the fact that this guy has rescued their world like 800 times now, they decide he's in cahoots with the troll who kidnapped the girl and they send him into the Stygian Abyss to retrieve her.
Thus the dungeon-crawling nature of the game is established, but there is more depth here than the usual dungeon crawl. You'll find a forgotten race of people living in the depths of the dungeon with whom you'll have to interact to eventually get the girl and get yourself out. Not only that, monsters may or may not attack you depending on their mood and on precedents you've set with your past actions, You also have all the various skills of the Ultima series such as sneaking past encounters, picking locks, repairing items and disarming traps. Your chosen character class also has a lot to do with how you'll approach various situations in the game.
Aside from the pioneering 3D the game uses fairly simple sprites for the GUI and characters, these aren't fantastic but they are colorful and passable to look at. Music is by "The Fat Man" George Sanger, always a reliable quality deliverer of soundtracks, and there's a limited "cues" system used with the music here similar to the shifting situations of the Wing Commander games.
The only real knock against the game is that it hasn't aged too well in terms of the interface. The natural setup for this sort of game would be to have you move with the arrow keys, a la Wolfy 3D or DOOM, and navigate the GUI using the mouse. But it's all one or the other - you have to either use the mouse for everything or use the keyboard and like a billion hotkeys for everything. The hotkeys method is just insane, so you'll likely settle for the mouse, which brings with it a lot of needless clicking to move about and transition between actions. It also isn't the most precise method of movement and can be frustrating when trying to line up with something, and combat is a little clunky. If you have the old-school chops to be used to such things, however, and never gave this one a try in its heyday, you will likely be pleasantly surprised by it.
* Bootstrike's Page
* Gameplay Video