- Awesome Music:
- The second game's soundtrack consists of a rather excellent set of variations on a Phrygian progression.
- The first game had surprisingly atmospheric music that was especially exceptional at the time of its release.
- Bizarro Episode: The first Ultima Underworld is difficult to fit in the rest of the series. There are numerous aspects of the lore which have no precedence in earlier games and neither those or events of the game are mentioned later (though Ultima IX was originally supposed to feature the Slasher of Veils). This is in large part due to the game starting out as an unconnected dungeon crawler which was rather forcibly turned into part of the Ultima series.
- Contested Sequel: There's quite a bit of debate regarding which of the two games is better. The general consensus, however, seems to be that Ultima Underworld 2 isn't as strong as its predecessor.
- By reducing a potion or scroll to a pile of debris, the player is rewarded with a clump of magical dust capable of endlessly casting the spell associated with the former item and never consuming itself. Daylight spells, potent heals, flying, and even Time Stop are possible. While it took a little effort in The Stygian Abyss (namely, hurling fireballs at said potion or scroll until destroyed), in Labyrinth of Worlds, the player could simply toss the potion against the wall until it became infinite arcane debris. The biggest problem soon becomes keeping track of all the outwardly identical piles of debris.
- One of the Plot Coupons from the first game, the Sword of Justice, is fairly easy to discover on the third floor of the Abyss (you are, in fact, required to find it to complete the game). Once you get it, it's equivalent in power to the second strongest weapon in the game and has the added benefit of never needing repair. This functionally breaks the admittedly varied weapon tree right until the end of the game, when you have to destroy the sword to continue.
- In the first game, it's possible to get your bartering skill so high that merchants will gleefully buy that one gold coin off you for this stack of identical gold coins.
- Good Bad Bugs: The above glitch of turning magic items into magical piles of debris with unlimited uses. Similarly, as the games use the damage state of an item as the state of decay for food, throwing fresh food at a wall for a couple of minutes will cause it to suddenly sprout mold or become full of worms.
- Hilarious in Hindsight: One of the characters in the first game is a mage named Naruto.
- Jerkass Woobie: Zak in the first game. Sure, he stole things (including the Taper of Sacrifice), but his incapacitating phobia of the dark makes it easy to pity him.
- Misaimed Fandom: At one point, the Florida Department of Corrections referenced the virtues of the Guardian from this game as something correctional employees should aspire to, apparently misunderstanding that the Guardian is the villain and that his "virtues" are corruptions of the Avatar's virtues, meant to portray the lands you visit in this game as authoritarian dystopias.
- Nightmare Fuel: The death sequence in the first game is pretty unsettling, especially if you played it as a kid: a number of skulls will zoom back and forth towards the screen, one of them finally filling the screen and turning out to have glittering red eyes. Turns into Sweet Dreams Fuel if you've planted the Silver Seed before dying: the skulls will vanish, and instead the Silver Sapling will zoom into view, before you come back to life at the spot where you planted it.
- Porting Disaster: Not technically a "port" per say, but the soundcard configuration in GOG's versions of the two games really messes up the music and some of the sound effects. Fortunately, there are ways of fixing this.
- "Seinfeld" Is Unfunny: To modern gamers, these two games may seem almost unplayable with their archaic and clunky control schemes and antiquated graphics and sound. These belie the fact that the Ultima Underworld games were arguably the original first person action adventure games, even predating Wolfenstein 3D, and they're still vast open world RPG quests. Before The Elder Scrolls there was Ultima Underworld.
- Squick: Everything about the Exiles in the first game. Their portraits, their names, the fact that they have no problem eating fellow sapients... That said, all the named Exiles in the game are non-hostile and quite friendly to the Avatar.
- Rotworm Stew, given that it's made from the flesh of large worms, though ironically it turns out to be very tasty.
- Unwinnable by Insanity: The Armageddon spell obliterates everything except the player, but it's pretty obvious that you should save before trying it.
- What an Idiot!: During your battle with Tyball in the first game, Tyball never thinks to tell the Avatar that he intends to sacrifice Arial only to stop the Slasher of Veils, instead preferring to gloat about his imminent victory. Really, the responsibility for his failure is all on him.
YMMV / Ultima Underworld