Awesome Music: Most of the tracks were just second-long creepy jingles but did a good job at setting the mood.
There is also the upbeat medieval music that plays during Ivar's fantasies about being a knight and when he's determined to confront the Count in order to save S.P.R.A.K..
Cult Classic: The show is worshipped by those who watched it as kids/teens. In fact, it's not unusual to hear of adult fans gathering their friends and then marathoning all the episodes in one go.
Fridge Logic: Which second grader carries around a voltmeter in his backpack? And lends it to a classmate on a whim?!
Harsher in Hindsight: The Counteffortlessly murdering Jean and Staffan is already pretty dark, even if it happens almost entirely offscreen. But watching that scene again with knowledge from the sequel series that Jean is the Count's illegitimate son, and both of them are aware of their relation, makes the latter's actions even more despicable, if not outright disturbing.
Episode 15. Lillan managing to get Leif near-gibbering with the urge to investigate what on earth could make that rock hover, before she just snatches it back saying "Secret". Shortly followed by a Funny Moment when he tries with a hammer.
The ghosts managing to overcome their life-long fear to face the Count head-on in Episode 21.
When the series was released, many found the Count's current form as a talking skeleton scary; in a "Behind the scenes" featurette, the computer designer explained that they purposely gave the Count weird eyebrows and three front teeth in an attempt to make him less intimidating.
The first PC game also qualifies for its target audience due to the spooky atmosphere (and the Jump Scare when the Count pops out of nowhere and seals the player in a dungeon).
Nightmare Retardant: The Count's odd face makes him look pretty silly to adults that watch the series, even those who found him scary when seeing him as kids.
2012 Sequel
Common Knowledge: No, the Count was NOT recast in the sequel because his original actor had died - he did not pass away until 2 years after the sequel had already aired on tv, and and he was still active is an actor pretty much up until the moment of his death. The reason behind the recast is most likely that the role was too physically demanding for a frail old man, and that it wouldn't make sense for what is essentially youth elixir to restore an undead person to an elderly state. Not to mention, by having Jean and the Count played by the same actor, it puts an emphasis on the familial connection between the two.
Franchise Original Sin: Felix Nordh pointed out in the conclusion of his review of the sequel that a lot of the problems in said sequel (bad acting, loads of plot holes, bad effects) existed in the first Greveholm, and were even worse in some areas. What seperates the two is that the original's script (despite how cheesy it is) at least fleshed out the characters so that the audience would care for them while the sequel never really did that and the few character traits that there are doesn't go anywhere, leading to the new characters being really thin.
Ho Yay: While Lillan and Dioda didn't have much chemistry in the original series, the sequel features oddly sapphic scenes of them holding hands, smiling and giggling while they look into each other's eyes (although they only refer to their relationship as "old friends").
They Wasted a Perfectly Good Character: Ivar goes from being a main character in the original series to showing up in exactly two scenes in the sequel that amount to little more than glorified cameos. While this decision likely stems from his actor preferring to work behind the camera rather than in front of it, it would have been very interesting to see him filling a mentor role similar to Lillan, since he'd have the advantage of being someone that used to be a much wilder and imaginative kid that has wisened up and become more responsible, as opposed to Lillan who stays relatively the same from the original series.
He also never gets to interact with Dioda in the sequel, meaning they squandered an opportunity to explore their dynamic now that Ivar is no longer a teenager.
Tough Act to Follow: The sequel is often considered a disappointment because it wasn't able to live up to its predecessor, especially considering the fact that more or less every plot thread in Greveholm had been resolved.
that plays during Ivar's fantasies about being a knight and when he's determined to confront the Count in order to save S.P.R.A.K..