- Big-Lipped Alligator Moment: The pre-credit sequence has Picard fretting on the bridge about Riker and Worf. We then see the pair sneaking about in a forest before being attacked by some skeleton guys. They fight and kill them, then Worf tries to attack Riker, Riker tells him not to... and they casually walk off the holodeck as the credits come up. It has absolutely nothing to do with the rest of the episode.
- It does have relevance, but the later call-back to it isn't very obvious. Worf can been seen muttering to himself "At ease, Lieutenant" after he nearly freaks out on the Yamato's repeating bridge, the same line Riker said to him when he got carried away in the holodeck. Still comes across as BLAM-like, since Worf is shown in later seasons being a lot more stoic/emotionally controlled most of the time, and nowhere near as driven to panic/frenzy from time-space weirdness as he is in this episode.
- Cliché Storm: A lot of familiar Star Trek tropes appear in the episode, including a Red Shirt Black Dude who Dies First, Worf behaving like an animal with a Hair-Trigger Temper, a Negative Space Wedgie the Enterprise crew is interested in exploring before becoming desperate to escape from it, and a Sufficiently Advanced Alien who wants to kill much of the crew just to satisfy its curiosity. However, it came early in TNG's run and was well-executed enough that it's able to get away with it for the most part.
- Glurge: Once again, Picard is happy to set off the auto-destruct but it takes Pulaski (of all people) to remind him what an overreaction that may be. Rather than 50% of the crew being killed, Picard will merrily slaughter 100%. (This is also one of those episodes that ignores the fact that there are civilians — including children — on board the ship.)
- Harsher in Hindsight: Worf remembers an old Klingon legend about a starship-devouring monster in regards to the situation at hand. Years later, another ship would run into the real one.
- Memetic Mutation: Haskell's over-the-top death scene has become a popular reaction gif.
- Narm: We have a frustrated Worf crying out "There is one bridge. ONE BRIDGE. ONE RIKER. ONE BRIDGE." Then proceeds to gargle some sort of growl as he fights with a door to keep it open.
- Narm Charm: The Nagilum entity looks...a bit goofy, and the early-80s CGI hasn't aged well, but it's fairly creepy in context, given how it looks almost human...but not quite.
YMMV / Star Trek: The Next Generation S2E2 "Where Silence Has Lease"